# Science & Research

**Type:** Topic
**Words:** 533

## About

Experiments, theories, and the building blocks of the physical world.

## Words by Level

### A1
- science — The study of the physical world through observation and experiment, covering subjects like physics, chemistry, and biology.; frequency rank 1531

### A2
- control — The power to direct, manage, or make decisions about something.; frequency rank 598
- energy — The strength and ability to be active without getting tired.; frequency rank 1232
- research — A careful study to discover new facts or information.; frequency rank 1572
- data — Facts and figures collected for analysis or to draw conclusions.; frequency rank 2029
- scientific — Relating to science or the way science is done.; frequency rank 3543
- chemical — A substance, such as an element or compound, used in or produced by chemistry.; frequency rank 4179
- atom — The smallest part of a chemical element that can exist.; frequency rank 9239
- energetic — Full of energy and eager to be active.; frequency rank 13015

### B1
- lab — A room or building equipped for scientific work; short for laboratory.; frequency rank 1632
- theory — A set of ideas that explains how or why something happens, supported by evidence.; frequency rank 1830
- reaction — The way you behave or feel because of something that has happened.; frequency rank 2912
- experiment — A scientific test done to discover something or to check whether an idea is true.; frequency rank 3016
- oxygen — A colourless, odourless gas that humans and animals need to breathe and that makes up part of the air.; frequency rank 3536
- discovery — Something that is found or learned for the first time.; frequency rank 4117
- analysis — The careful study of something by examining its parts in detail.; frequency rank 4167
- react — To behave in a particular way because of something that has happened.; frequency rank 4677
- observe — To watch someone or something carefully.; frequency rank 4930
- formula — A mathematical or scientific rule written with symbols.; frequency rank 5057
- element — One of the parts that together make up a whole.; frequency rank 5109
- genetic — Relating to genes or to the genes you inherit from your parents.; frequency rank 5133
- physics — The science that studies matter, energy, and how they affect each other.; frequency rank 5210
- chemistry — The science that studies what substances are made of and how they change.; frequency rank 5497
- allergic — Having a bad physical reaction to a particular substance.; frequency rank 5531
- laboratory — A room or building equipped for scientific research, experiments, or analysis.; frequency rank 6012
- biology — The science that studies living things such as plants and animals.; frequency rank 7792
- breakthrough — An important discovery or sudden advance that overcomes a major obstacle.; frequency rank 8623
- reactor — A person who responds to a suggestion, stimulation or other influence.; frequency rank 8995
- plasma — (physical chemistry) a fourth state of matter distinct from solid or liquid or gas and present in stars and fusion reactors; frequency rank 9162
- meteor — a streak of light produced when a small piece of matter from space enters Earth's atmosphere and becomes intensely hot; frequency rank 9197
- enthusiastic — Showing great excitement and interest in something.; frequency rank 10618
- extinction — The situation in which a species or group no longer exists.; frequency rank 11044
- molecular — relating to or produced by or consisting of molecules; frequency rank 12289
- dioxide — A chemical compound that has two oxygen atoms in each molecule.; frequency rank 12561
- genetics — The branch of biology that studies how characteristics are passed from parents to children.; frequency rank 15499
- biologist — a scientist who studies living organisms and the processes of life; frequency rank 17773
- molecule — The smallest unit of a substance that still has all its chemical properties, made of two or more atoms joined together.; frequency rank 18594
- orbital — relating to an orbit or to motion around another body; frequency rank 19044
- geology — The science that studies the structure of the earth and its rocks.; frequency rank 19325
- geologist — a specialist in geology; frequency rank 19496
- oxide — a chemical compound of oxygen with another element; frequency rank 21137
- science fiction

### B2
- vital — Extremely important; essential.; frequency rank 4462
- evolution — The gradual process by which something changes and develops over time.; frequency rank 5967
- beta — preliminary or testing stage of a software or hardware product; frequency rank 9573
- gamma — the 3rd letter of the Greek alphabet; frequency rank 9580
- cellular — characterized by or divided into or containing cells or compartments (the smallest organizational or structural unit of an organism or organization); frequency rank 13298
- blooming — Producing flowers; in flower.; frequency rank 13756
- meteorite — a piece of rock or metal from space that survives passage through an atmosphere and reaches the ground; frequency rank 15568
- scientifically — From the point of view of science.; frequency rank 15691
- lifeless — Dead, or appearing to be dead.; frequency rank 16186
- ether — a substance once thought to fill space and carry light or electromagnetic waves; frequency rank 16966
- ion — an atom or group of atoms with a positive or negative electrical charge because it has lost or gained electrons; frequency rank 16977
- sulfur — A bright yellow chemical element (symbol S) with a strong smell, used in matches, gunpowder, and many industrial products.; frequency rank 17888
- relativity — (physics) The scientific theory that space and time are not fixed but depend on the observer's motion.; frequency rank 18393
- supernova — an extremely energetic stellar explosion that makes a star suddenly become vastly more luminous; frequency rank 18683
- neutron — an elementary particle with 0 charge and mass about equal to a proton; frequency rank 18928
- telepathic — communicating without apparent physical signals; frequency rank 20321
- regeneration — Rebuilding or restructuring; large scale repair or renewal; revitalisation.; frequency rank 20858
- wavelength — a shared orientation leading to mutual understanding; frequency rank 21027
- reproductive — producing new life or offspring; frequency rank 21048
- catalyst — Something or someone that causes an important change or event to happen.; frequency rank 21475
- digestion — learning and coming to understand ideas and information; frequency rank 21513
- enzyme — a protein or RNA molecule that catalyzes a biochemical reaction without being consumed by it; frequency rank 21762
- decomposition — The process of rotting and breaking down, caused by bacteria or fungi.; frequency rank 24341
- subatomic — of or relating to constituents of the atom or forces within the atom; frequency rank 26462
- vigorously — With great energy, force, or determination.; frequency rank 27268
- hydraulics — the science and engineering of liquids in motion and their use to transmit force; frequency rank 27470
- beaker — a straight-sided, flat-bottomed laboratory container, usually with a pouring lip; frequency rank 28552
- enthusiastically — In a way that shows great excitement and interest.; frequency rank 35898
- naturalist — a biologist knowledgeable about natural history (especially botany and zoology); frequency rank 37506
- spreadsheet — A computer program that organizes data in a grid of rows and columns for calculation and analysis.; frequency rank 37742
- carbonate — a salt or ester of carbonic acid, typically containing the carbonate ion CO3^2-; frequency rank 38773
- gaseous — existing in the physical state of a gas rather than a solid or liquid; frequency rank 40096
- evaporation — the process by which a liquid changes into a gas, especially at its surface; frequency rank 43309
- biotechnology — The use of living things, such as cells or bacteria, to make medicines, foods, and other useful products.; frequency rank 49318
- morphology — the branch of biology that deals with the structure of animals and plants; frequency rank 52582
- newtonian — relating to Isaac Newton, his scientific work, or the laws and methods derived from it; frequency rank 63028
- experimenter — a scientist or researcher who conducts an experiment; frequency rank 66023
- interbreeding — reproduction between animals or plants from different populations, breeds, varieties, or closely related species; frequency rank 68909
- irradiation — the process of exposing a person, organism, food, or material to ionizing radiation; frequency rank 80097
- unfertilized — biology: not fertilized by the fusion of male and female reproductive cells; frequency rank 143875
- hybridism — the production of hybrids by crossing different species, varieties, or breeds

### C1
- gravity — The natural force that pulls objects toward the earth or toward each other.; frequency rank 4160
- hydrogen — The lightest chemical element (symbol H), a colorless, odorless, highly flammable gas.; frequency rank 8914
- intercourse — Communication, conversation.; frequency rank 10158
- fusion — The act of joining separate things into one, or the result of doing so.; frequency rank 10433
- volcanic — of or relating to igneous rock produced by eruption and solidified on or near the earth's surface; frequency rank 10763
- thermal — relating to heat, temperature, or the transfer of heat; frequency rank 11535
- sap — To slowly drain away someone's strength, energy, or determination.; frequency rank 12146
- fetus — An unborn or unhatched vertebrate showing signs of the mature animal.; frequency rank 14592
- lobe — (anatomy) a somewhat rounded subdivision of a bodily organ or part; frequency rank 14633
- embryo — a plant, animal, or human in the earliest stages of development; frequency rank 18971
- metabolism — the set of chemical processes by which a living organism converts substances into energy and materials needed for life, growth, and repair; frequency rank 19092
- genome — The complete set of genetic information in an organism.; frequency rank 19233
- bisexual — in biology, involving or possessing both male and female sexes or reproductive structures; frequency rank 19677
- antimatter — matter composed of antiparticles corresponding to the particles in ordinary matter; frequency rank 19759
- interstellar — situated, occurring, or traveling between stars; frequency rank 21075
- ultraviolet — relating to electromagnetic radiation with wavelengths shorter than visible violet light, conventionally about 10 to 400 nanometers; frequency rank 21092
- pathway — A path or track for walking.; frequency rank 22179
- alchemist — a person who practices alchemy, historically seeking transformations such as turning base metals into gold; frequency rank 22379
- gusto — Great energy and enthusiastic enjoyment in doing something.; frequency rank 22550
- statistical — Relating to statistics or the analysis of numerical data.; frequency rank 22583
- iodine — the chemical element with atomic number 53, a dark halogen that forms a violet vapor when heated; frequency rank 22658
- radioactivity — Spontaneous emission of ionizing radiation as a consequence of a nuclear reaction, or directly from the breakdown of an unstable nucleus.; frequency rank 22820
- prism — a transparent optical element with flat faces that refracts light, often separating it into colors; frequency rank 23725
- optics — the branch of physics concerned with light, vision, and the behavior of electromagnetic radiation; frequency rank 24373
- amino — relating to or containing the nitrogen-based amino group, especially in an amino acid; frequency rank 27322
- fulcrum — the fixed support or pivot about which a lever turns; frequency rank 29224
- empirical — Based on observation, experiment, or real experience rather than on theory.; frequency rank 30528
- formulate — To create or develop a plan, idea, or theory through careful thought.; frequency rank 31095
- saturation — the state or process of being completely soaked, filled, or supplied to capacity; frequency rank 31230
- biochemical — relating to biochemistry or to the chemical substances and processes that occur in living organisms; frequency rank 31314
- calorie — A unit that measures the energy in food and drink.; frequency rank 31844
- ammonium — the ion NH4 derived from ammonia; frequency rank 33102
- mutate — to undergo a change in genetic material or another heritable biological change; frequency rank 33290
- linguistic — consisting of or related to language; frequency rank 36546
- aromatic — (chemistry) of or relating to or containing one or more benzene rings; frequency rank 37356
- concealment — The practice of keeping secrets.; frequency rank 38361
- reversible — capable of assuming or producing either of two states; frequency rank 38915
- reliance — certainty based on past experience; frequency rank 39131
- linguistics — the scientific study of human language, including its sounds, structures, meanings, use, acquisition, history, and variation; frequency rank 40824
- heredity — Hereditary transmission of the physical and genetic qualities of parents to their offspring; the biological law by which living beings tend to repeat their characteristics in their descendants.; frequency rank 42898
- unrestrained — not subject to restraint; frequency rank 45511
- fermentation — a metabolic process in which microorganisms or enzymes convert organic substances, often sugars, without oxygen; frequency rank 46778
- decanter — A receptacle for decanted liquor, especially a crystal bottle with a stopper.; frequency rank 47513
- rigidity — The quality or state of being rigid; lack of pliability; the quality of resisting change of physical shape.; frequency rank 47605
- stargazer — a person who observes the stars, especially an amateur astronomer; frequency rank 47644
- unscientific — not consistent with the methods or principles of science; frequency rank 49375
- tertiary — coming next after the second and just before the fourth in position; frequency rank 50291
- paleontologist — a scientist who studies fossils and life from past geological periods; frequency rank 53664
- lackluster — Not impressive; dull and lacking energy or excitement.; frequency rank 54584
- materially — with respect to material aspects; frequency rank 56552
- cathode — a negatively charged electrode that is the source of electrons entering an electrical device; frequency rank 58465
- retardation — Ellipsis of mental retardation.; frequency rank 59178
- resonator — an object, chamber, or part of an instrument that vibrates at particular frequencies and strengthens or shapes a sound; frequency rank 60817
- incubate — to keep eggs warm under conditions that allow embryos to develop and hatch; frequency rank 61734
- ionization — the generation of one or more ions from atoms, molecules, or other chemical entities, for example through electron loss or gain or through dissociation; frequency rank 62469
- sunspot — a temporary dark region on the Sun's photosphere that is cooler than its surroundings and has intense magnetic activity; frequency rank 64347
- variability — the quality of being subject to variation; frequency rank 70541
- experimentally — in an experimental fashion; frequency rank 75753
- unverified — not yet checked or confirmed as accurate, authentic, or true; frequency rank 89252
- plasticity — the capacity of a material to be reshaped permanently without breaking; frequency rank 89839
- magnetize — to give a material the properties of a magnet, or to become magnetic; frequency rank 94439
- neutralization — The act of stopping something from having an effect by balancing it out.; frequency rank 101113
- suborbital — following a trajectory that rises into space but does not complete an orbit; frequency rank 105763
- pneumatics — the branch of mechanics concerned with gases and their use to transmit force, especially through compressed air; frequency rank 106531
- attractor — a person, thing, or quality that draws interest, attention, or other things toward it; frequency rank 112397
- crustal — relating to or forming the outer crust of the Earth, Moon, or another planetary body; frequency rank 115250
- ionize — to convert an atom, molecule, or other chemical entity into one or more ions; frequency rank 140717
- uncharged — having no net electric charge; electrically neutral; frequency rank 198815
- lethargically — In a slow, tired way, without energy.; frequency rank 1227534

### C2
- galaxy — a vast gravitationally bound system of stars, gas, dust, dark matter, and other astronomical objects; frequency rank 4480
- ivy — Any of several woody, climbing, or trailing evergreen plants of the genus Hedera.; frequency rank 5706
- coroner — A public official who presides over an inquest into unnatural deaths, and who may have (or historically had) additional powers such as investigating cases of treasure trove.; frequency rank 6269
- mutant — an organism, cell, gene, or other biological entity that carries a mutation; frequency rank 6625
- asteroid — a natural rocky or metallic body smaller than a planet that orbits a star, especially one orbiting the Sun; frequency rank 8725
- crate — to put into a crate; frequency rank 9398
- radioactive — exhibiting or caused by radioactivity; frequency rank 9661
- suction — the process or force by which reduced pressure draws in a fluid or makes surfaces adhere; frequency rank 10672
- Martian — of or relating to the planet Mars or its actual or imagined inhabitants; frequency rank 10770
- unicorn — A mythical horse, widely believed to exist until the 17th century, with a single, straight, spiraled horn projecting from its forehead.; frequency rank 11679
- hypothesis — An idea put forward to explain something, which can then be tested.; frequency rank 11795
- watermelon — An environmentalist with socialist leanings, an ecosocialist.; frequency rank 12225
- gravitational — Relating to or caused by gravity.; frequency rank 12389
- infrared — using or relating to electromagnetic wavelengths longer than visible red light but shorter than microwaves; frequency rank 12868
- zodiac — the belt of the sky centered on the ecliptic through which the sun, moon, and visible planets appear to move; frequency rank 14055
- nebula — an interstellar cloud of gas and dust, often associated with the formation or death of stars; frequency rank 15215
- elk — large northern deer with enormous flattened antlers in the male; frequency rank 16429
- chameleon — A small to mid-size reptile, of the family Chamaeleonidae, and one of the best known lizard families able to change color and project its long tongue.; frequency rank 17427
- Neanderthal — a member of an extinct human species, Homo neanderthalensis, that lived in Europe and western Asia until about 40,000 years ago; frequency rank 19202
- evasion — nonperformance of something distasteful, as by deceit or trickery, that you are supposed to do; frequency rank 19953
- inconclusive — Not conclusive, not leading to a conclusion.; frequency rank 20653
- albino — born with albinism and therefore having little or no melanin pigmentation; frequency rank 21390
- stardust — fine particles of matter originating in stars or present in interstellar space; frequency rank 21808
- Jurassic — relating to the second period of the Mesozoic Era, approximately 201 to 145 million years ago; frequency rank 23307
- bray — to laugh loudly and harshly; frequency rank 24247
- skylight — a window in a roof to admit daylight; frequency rank 25096
- helix — a three-dimensional curve that winds around an axis at a constant slope, as in a screw or spiral staircase; frequency rank 25108
- stigma — a mark of shame or social disapproval; frequency rank 25352
- phonograph — A record player.; frequency rank 25675
- fluorescent — emitting visible or other electromagnetic radiation while excited by absorbed radiation or energetic particles, with the emission usually ending almost at once when excitation stops; frequency rank 25926
- larynx — A hollow muscular organ of the neck of mammals situated just below where the tract of the pharynx splits into the trachea and the oesophagus. It is involved in breath control and protection of the trachea, and, as it houses the vocal cords, sound production.; frequency rank 28129
- crossover — a crossing or transition from one place, group, activity, or system to another; frequency rank 30206
- elliptical — In a shape of, or reminding of, an ellipse; oval.; frequency rank 32332
- paraffin — A petroleum-based thin and colourless fuel oil.; frequency rank 33197
- cosmology — the scientific study of the origin, structure, development, and possible fate of the universe; frequency rank 33560
- tuff — rock formed from compacted or cemented volcanic ash and other fine volcanic fragments; frequency rank 33771
- anatomical — of or relating to the structure of the body; frequency rank 33854
- shingle — cover with shingles; frequency rank 37329
- transcendental — existing outside of or not in accordance with nature; frequency rank 40149
- spectrometer — an instrument that separates radiation, particles, or signals into a spectrum and measures their intensity or abundance by wavelength, frequency, energy, or mass-to-charge ratio; frequency rank 40835
- levitation — the phenomenon of a person or thing rising into the air by apparently supernatural means; frequency rank 41031
- fertilization — the union of male and female gametes to begin the development of a new organism; frequency rank 41312
- geneticist — a scientist who specializes in genes, heredity, and genetic variation; frequency rank 41434
- amoeba — a single-celled organism that changes shape and moves or feeds by extending pseudopodia; frequency rank 42539
- symbiosis — The occurrence of two different or opposing things in the same time and place.; frequency rank 42748
- nitric — relating to nitrogen, especially nitrogen in a relatively high oxidation state; frequency rank 43011
- filament — a very thin thread or fiber of natural or manufactured material; frequency rank 43970
- thermodynamics — The science of the conversions between heat and other forms of energy.; frequency rank 44278
- forcible — impelled by physical force especially against resistance; frequency rank 44743
- graviton — a hypothetical massless spin-2 boson that would be the quantum carrier of gravity in a quantum theory of the gravitational field; frequency rank 44946
- deuterium — An isotope of hydrogen with one proton and one neutron in each atom - 21H.; frequency rank 45234
- tinge — color lightly; frequency rank 46568
- electromagnetism — magnetism produced by an electric current; frequency rank 47053
- basalt — the commonest type of solidified lava; frequency rank 47627
- quasar — an extremely luminous active galactic nucleus powered by matter falling into a supermassive black hole; frequency rank 48360
- electrostatic — relating to stationary electric charges, the fields and forces they produce, or devices that use those forces; frequency rank 48843
- ornithologist — a scientist who studies birds; frequency rank 50789
- sedimentary — resembling or containing or formed by the accumulation of sediment; frequency rank 51285
- bacillus — any rod-shaped bacterium; frequency rank 51706
- paleontology — the scientific study of prehistoric life through fossils and other remains preserved in rocks; frequency rank 52491
- verifiable — capable of being tested, verified or falsified, by experiment or observation; frequency rank 53949
- lactic — relating to, derived from, or occurring in milk; frequency rank 58603
- sceptic — someone who habitually doubts accepted beliefs; frequency rank 59110
- entomology — the scientific study of insects, including their classification, anatomy, behavior, ecology, and relationships with humans; frequency rank 59509
- electrolysis — The chemical change produced by passing an electric current through a conducting solution or a molten salt.; frequency rank 62346
- vivisection — surgical cutting into, or other invasive experimentation on, a living animal or organism for scientific research; frequency rank 63151
- vehement — marked by extreme intensity of emotions or convictions; frequency rank 63202
- phonetic — of or relating to the scientific study of speech sounds; frequency rank 64239
- chromosomal — relating to, carried on, or caused by chromosomes; frequency rank 65087
- prussic — dated in chemistry: relating to hydrogen cyanide or hydrocyanic acid, especially in the term prussic acid; frequency rank 65322
- gravitationally — In a way relating to or caused by gravity.; frequency rank 65460
- elliptic — characterized by extreme economy of expression or omission of superfluous elements; frequency rank 65732
- hyperbolic — enlarged beyond truth or reasonableness; frequency rank 66169
- mitosis — cell-nuclear division in which duplicated chromosomes separate into two genetically equivalent nuclei; frequency rank 66597
- ornithology — the branch of zoology concerned with the scientific study of birds; frequency rank 67382
- extant — Still existing; not lost or destroyed.; frequency rank 67704
- luminosity — the quality or degree of giving off or reflecting light; brightness; frequency rank 67936
- igneous — geology: formed when molten magma or lava cools and solidifies; frequency rank 68199
- anatomist — One who studies, teaches, writes on, or does research on anatomy and anatomical structures.; frequency rank 68758
- positron — an elementary particle with positive charge; frequency rank 71069
- alchemical — relating to alchemy, an early tradition concerned with transforming matter; frequency rank 73580
- leaven — A substance, such as yeast, added to dough to make it rise.; frequency rank 74646
- trilobite — an extinct Paleozoic marine arthropod with a segmented exoskeleton divided lengthwise into three lobes; frequency rank 75212
- falsification — the showing or proving that a claim, hypothesis, or statement is false; frequency rank 77571
- foxfire — the faint glow produced by bioluminescent fungi growing on decaying wood; frequency rank 79625
- costal — anatomy: relating to a rib or the ribs; frequency rank 80369
- Silurian — relating to the geological period between the Ordovician and Devonian, about 444 to 419 million years ago; frequency rank 80461
- pleistocene — the geological epoch from about 2.58 million to 11,700 years ago, preceding the Holocene; frequency rank 81957
- protoplasm — the living contents of a cell, including its cytoplasm and nucleus; frequency rank 82059
- cyclotron — a circular particle accelerator in which a magnetic field bends charged particles into an expanding spiral and an alternating electric field accelerates them whenever they cross the gap between electrodes; frequency rank 83695
- spectroscope — an instrument that disperses electromagnetic radiation into its component wavelengths so that the resulting spectrum can be viewed or examined, especially in visible light; frequency rank 83801
- parthenogenesis — reproduction in which an embryo develops from an unfertilized egg; frequency rank 84386
- photoelectric — of or pertaining to photoelectricity; frequency rank 85263
- fluorescence — The emission of light (or other electromagnetic radiation) by a material when stimulated by the absorption of radiation or of a subatomic particle.; frequency rank 85410
- artesian — of groundwater that is confined under pressure and can rise in a well above the level at which it is first reached; frequency rank 86319
- hybridization — the crossing of genetically different organisms, varieties, or species to produce hybrids; frequency rank 86662
- pion — any of three unstable spin-zero mesons, positively charged, negatively charged, or neutral, made from combinations of up and down quarks and antiquarks; frequency rank 88034
- electrochemical — of or involving electrochemistry; frequency rank 88125
- relativistic — relating or subject to the special or the general theory of relativity; frequency rank 88195
- spectrograph — an instrument that separates radiation, sound, or charged particles into a spectrum and records or maps the resulting distribution; frequency rank 88251
- prostration — an abrupt failure of function or complete physical exhaustion; frequency rank 88316
- refractive — relating to refraction or to the bending of light, sound, or another wave; frequency rank 88581
- pipette — a narrow graduated tube used to measure or transfer a small quantity of liquid; frequency rank 89353
- Carboniferous — relating to the geological period between the Devonian and Permian, about 359 to 299 million years ago; frequency rank 89717
- nodule — a small rounded lump, knot, or mass in tissue, rock, or another material; frequency rank 89927
- phosphor — a substance that emits light after being excited by radiation or another form of energy, as in fluorescent lamps and display screens; frequency rank 90079
- lodestone — a naturally magnetized piece of magnetite capable of attracting iron; frequency rank 91024
- chaffinch — small European finch with a cheerful song; frequency rank 91236
- psychical — Performed by or pertaining to the psyche (the mind, spirit, or both): mental, psychic.; frequency rank 91846
- tannin — any of a group of astringent plant compounds that bind proteins and are found in bark, leaves, fruit, tea, and wine; frequency rank 91862
- precession — the slow conical motion of a spinning body's rotation axis, usually caused by an external torque; frequency rank 92442
- parasitical — relating to, caused by, or living as a parasite; parasitic; frequency rank 94051
- ammonite — one of the coiled chambered fossil shells of extinct mollusks; frequency rank 95190
- interferometer — an instrument that superimposes two or more waves and analyzes their interference pattern to make precise measurements of distance, wavelength, refractive index, or related quantities; frequency rank 95727
- phrenology — historical: a discredited system that claimed a person's character and mental faculties could be read from the shape of the skull; frequency rank 97430
- muon — an unstable elementary lepton with about 207 times the electron's mass; the negative muon has the electron's charge, and its antiparticle is the positive antimuon; frequency rank 99639
- ethnologist — a scholar who studies and compares peoples, cultures, and social institutions, especially within the field of ethnology; frequency rank 99984
- metamorphic — relating to rock altered by intense heat, pressure, or chemically active fluids without fully melting; frequency rank 102956
- stalactite — an icicle-shaped mineral deposit that hangs from the roof of a cave; frequency rank 103588
- stria — a narrow stripe, streak, or band, especially one of a parallel series in tissue, plumage, or another patterned surface; frequency rank 103620
- Devonian — the geological period of the Paleozoic Era between the Silurian and Carboniferous periods, about 419 to 359 million years ago; frequency rank 103919
- plutonic — of igneous rock formed when magma cools and solidifies deep below the earth's surface; frequency rank 108133
- corpuscle — a blood cell, especially a red or white blood cell; now chiefly used in older or nontechnical language; frequency rank 108264
- alluvial — Pertaining to the soil deposited by a stream.; frequency rank 109219
- undifferentiated — not divided, distinguished, or developed into different parts or types; frequency rank 109903
- meson — a hadron with integer spin, conventionally composed of a quark and an antiquark bound by the strong interaction; pions and kaons are mesons; frequency rank 110902
- refract — to make light, sound, or another wave change direction as it passes between media; frequency rank 111062
- electrolytic — of or concerned with or produced by electrolysis; frequency rank 112012
- fallibility — The state of being prone to error.; frequency rank 112440
- ichthyologist — a scientist or specialist who studies fish; frequency rank 112648
- monad — An ultimate atom, or simple, unextended point; something ultimate and indivisible.; frequency rank 113899
- spectroscopic — relating to spectroscopy or to the production, measurement, or analysis of spectra; frequency rank 115338
- breccia — rock composed of angular fragments cemented together in a finer-grained matrix; frequency rank 115695
- datum — one item of factual information used for measurement or reasoning; frequency rank 116109
- mutagenic — capable of causing genetic mutation, or relating to the production of mutations; frequency rank 116676
- prescience — Knowledge of events before they take place.; frequency rank 118245
- stratification — the formation, arrangement, or classification of something into distinct layers; frequency rank 119054
- hydrodynamic — relating to the motion of liquids and the forces acting on bodies in moving liquids; frequency rank 119490
- galvanism — electricity produced by chemical action, especially as understood in early electrical science; frequency rank 120099
- unverifiable — not capable of being checked, confirmed, or established as true by available evidence or method; frequency rank 122956
- ecliptic — the great circle on the celestial sphere representing the Sun's apparent yearly path; frequency rank 127064
- atavism — the reappearance in an organism of a trait associated with a remote ancestor; frequency rank 128054
- phlogiston — a hypothetical fire-like substance once thought to exist in combustible materials and to be released during burning; frequency rank 130167
- vibratory — involving, characterized by, or causing rapid back-and-forth motion or vibration; frequency rank 131048
- paleontological — relating to paleontology or to the study of life in the geological past through fossils; frequency rank 131652
- mineralogist — a scientist who studies the formation, composition, properties, and classification of minerals; frequency rank 131862
- synchrotron — a circular particle accelerator in which radiofrequency electric fields accelerate charged particles while a synchronized magnetic field keeps them on a fixed closed path as their energy increases; frequency rank 131925
- engram — A postulated physical or biochemical change in neural tissue that represents a memory.; frequency rank 133302
- phosphorescence — the emission of light by a substance that continues after the source of excitation has been removed; frequency rank 133580
- Eocene — relating to the geological epoch from about 56 to 34 million years ago, between the Paleocene and Oligocene; frequency rank 134095
- epistemology — The branch of philosophy dealing with the study of knowledge; the theory of knowledge, asking such questions as "What is knowledge?", "How is knowledge acquired?", "What do people know?", "How do we know what we know?", "How do we know it is true?", and so on.; frequency rank 136136
- lamina — a thin layer, plate, sheet, or scale of material; frequency rank 138512
- anode — the electrode at which oxidation occurs in an electrochemical cell; it is negative in a cell supplying current and positive when external power drives the reaction; frequency rank 138880
- gibbous — having more than half but less than all of the visible disk illuminated, especially of the moon; frequency rank 139194
- radioisotope — a radioactive isotope of an element, whose unstable nuclei decay and emit radiation; frequency rank 139845
- albumen — the white part of an egg; frequency rank 141765
- inhere — To be inherent; to be an essential or intrinsic part of; to be fixed or permanently incorporated with something.; frequency rank 141939
- perihelion — The point in the elliptical orbit of a comet, planet, etc., where it is nearest to the Sun.; frequency rank 142905
- paleozoic — of or relating to or denoting the Paleozoic era; frequency rank 144869
- evolutionist — a person who accepts, studies, or advocates the theory of biological evolution; frequency rank 147059
- embryology — the branch of biology that studies the formation and early development of living organisms; frequency rank 148627
- meiosis — cell division in which one diploid cell undergoes two divisions to produce four haploid cells; frequency rank 151125
- mineralogy — the branch of geology that studies minerals, including their composition, structure, properties, and classification; frequency rank 152823
- globule — a very small round mass, particle, or drop of a liquid or softened solid; frequency rank 153642
- bacteriologist — a scientist who specializes in the study of bacteria; frequency rank 154203
- polestar — the North Star, used as a fixed point for finding direction; frequency rank 157048
- periodicity — the quality of recurring at regular intervals; frequency rank 157682
- pliocene — the geological epoch about 5.3 to 2.6 million years ago, immediately before the Pleistocene; frequency rank 158237
- geocentric — treating Earth as the center, especially in an astronomical model of the universe; frequency rank 158933
- autosomal — relating to an autosome, or inherited through a chromosome other than a sex chromosome; frequency rank 163307
- vivisect — to operate on or dissect a living animal for scientific investigation; frequency rank 164155
- vivisectionist — a person who practices, advocates, or defends vivisection; frequency rank 166141
- reflexion — Uncommon spelling of reflection.; frequency rank 166229
- dualism — Duality; the condition of being double.; frequency rank 166761
- dynamical — relating to dynamics, forces, or the laws governing motion and change; frequency rank 170148
- undulation — a smooth rising-and-falling or back-and-forth movement like a wave; frequency rank 179446
- polypeptide — a chain of amino acids joined by peptide bonds, forming all or part of a protein; frequency rank 181255
- capitation — A system of remuneration for providers of health care, in which providers enroll patients as permanent clients and receive a fixed (and capped) periodic payment for each enrollee (i.e., per capita).; frequency rank 181736
- antiproton — the antiparticle of the proton, with the same mass but a negative electric charge; frequency rank 182284
- luminiferous — producing or transmitting light; luminous.; frequency rank 183312
- compressive — that compresses; frequency rank 188188
- orrery — a mechanical model that shows the relative positions and movements of bodies in the solar system; frequency rank 188369
- biophysical — relating to biophysics or to the application of physical principles and methods to biological systems; frequency rank 188754
- heliocentric — treating the sun as the center, especially in an astronomical model of the solar system; frequency rank 189503
- calorific — Containing a lot of calories and likely to be fattening.; frequency rank 190905
- kinematic — relating to motion considered without reference to the forces or masses that cause it; frequency rank 191491
- unobservable — not capable of being directly seen, measured, detected, or otherwise observed; frequency rank 192642
- vesicle — a small membrane-bound sac or cavity in a cell or organism, often containing fluid or another substance; frequency rank 195827
- extrinsic — not forming an essential part of a thing or arising or originating from the outside; frequency rank 204689
- plasm — biology, now rare: the living substance of a cell; protoplasm; frequency rank 204709
- transuranic — of a chemical element, having an atomic number greater than uranium's atomic number of 92; frequency rank 206808
- anatomize — to analyze a subject, argument, or character in minute detail; frequency rank 207613
- effervesce — to give off bubbles of gas; to fizz or foam; frequency rank 208363
- lenticular — shaped like a lens, especially convex on both sides; frequency rank 214454
- calcareous — Resembling, containing, or composed of calcium carbonate or limestone; chalky.; frequency rank 217951
- karyotype — the complete chromosome set of an individual or species, considered by number and visible structure; frequency rank 221634
- tapetum — a reflective or pigmented layer of tissue behind or within the retina of the eye; frequency rank 223496
- hermaphroditism — in biology, the condition of having both male and female reproductive organs, either simultaneously or at different life stages; frequency rank 227866
- supernatant — lying or floating above a denser liquid, sediment, or precipitate; frequency rank 228892
- antiparticle — a subatomic particle with the same mass and spin as another particle but opposite charge or other quantum numbers; frequency rank 229007
- hybridize — to cross genetically different organisms, varieties, or species, or to produce hybrid offspring; frequency rank 231589
- substratum — a layer of material, especially rock or soil, lying beneath another layer; frequency rank 233429
- aphelion — the point in the orbit of a planet, comet, or other body at which it is farthest from the Sun; frequency rank 235902
- submicroscopic — too small to be seen with an ordinary microscope; smaller than microscopic scale; frequency rank 238084
- homologous — similar in position, structure, or origin, especially because of shared ancestry; frequency rank 238852
- lamella — a thin plate, layer, membrane, or sheet forming part of a biological, mineral, or manufactured structure; frequency rank 244656
- pubescence — A covering of fine, soft hairs.; frequency rank 253475
- metaphase — the stage of mitosis or meiosis in which condensed chromosomes align before being separated; frequency rank 253978
- Miocene — the geological epoch from about 23 million to 5.3 million years ago, within the Neogene Period; frequency rank 257126
- suborder — taxonomy: a rank below an order and above an infraorder, used to divide a biological order into smaller groups; frequency rank 263879
- integument — a natural outer covering that protects an organism or one of its parts, such as skin, a shell, or a seed coat; frequency rank 264054
- homology — similarity between structures, genes, or features because they derive from a common evolutionary ancestor; frequency rank 267603
- convolution — a twist, coil, or fold, especially one of the folds on the surface of the brain; frequency rank 280973
- deuteron — the nucleus of a deuterium, or hydrogen-2, atom, consisting of one proton bound to one neutron; frequency rank 284552
- homozygous — having two identical alleles at a particular gene locus; frequency rank 289935
- branchial — relating to, resembling, or serving as gills; frequency rank 294529
- polymorphism — the occurrence of two or more distinct forms or genetic variants within a population; frequency rank 299911
- hygrometer — an instrument for measuring humidity, especially the relative humidity of the air; frequency rank 307972
- coccus — a bacterium with a spherical or roughly spherical shape; frequency rank 326178
- exogenous — originating outside an organism, system, or process; frequency rank 335120
- contiguity — A state in which two or more physical objects are physically touching one another or in which sections of a plane border on one another.; frequency rank 350511
- quantize — physics: to restrict a physical quantity or system to discrete allowed values or states; frequency rank 356743
- positronium — an unstable exotic atom consisting of an electron bound to its antiparticle, a positron, with no atomic nucleus; frequency rank 362649
- evolutionism — a philosophical or social doctrine that treats evolution as a universal process, often identified with progress; frequency rank 369295
- psychophysiology — the study of relationships between psychological processes and physiological activity; frequency rank 376004
- scoria — rough, dark, porous lava formed when gas-rich molten rock cools; frequency rank 391683
- monism — The doctrine that there is a single source of political authority, especially that the church is subordinate to the state or vice versa.; frequency rank 392326
- geocentrism — the astronomical model or belief that Earth is stationary at the center of the universe or of the motions of the heavenly bodies; frequency rank 415465
- fecundation — fertilization through the union of male and female reproductive cells; frequency rank 436645
- pseudopod — a temporary projection of a cell's cytoplasm used for movement, feeding, or engulfing material; frequency rank 446073
- heterozygous — having two different alleles at a particular gene locus; frequency rank 454721
- atomistic — Of or pertaining to atoms or to atomism.; frequency rank 464958
- mutational — relating to, caused by, or resulting from genetic mutation; frequency rank 510755
- unisexual — having the reproductive characteristics or organs of only one sex rather than both; frequency rank 518777
- heterozygote — an organism or cell having two different alleles at a particular gene locus; frequency rank 528032
- isotropy — the property of a system or medium whose relevant physical or statistical properties are the same in every direction; invariance under rotation at a given point; frequency rank 536960
- slaty — of the color of slate or granite; frequency rank 555627
- centromere — the constricted region of a chromosome where the kinetochore forms and sister chromatids remain joined during cell division; frequency rank 559481
- parthenogenetic — produced by or relating to reproduction in which an organism develops from an unfertilized egg; frequency rank 592784
- mineralize — to convert a substance into mineral or inorganic form, as in fossilization, bone formation, or carbon storage; frequency rank 632606
- conchologist — a person who studies or collects mollusc shells, especially for scientific classification; frequency rank 634542
- triturate — to crush, rub, or grind a substance thoroughly into fine particles or powder; frequency rank 637260
- pellicle — a very thin skin, membrane, or film covering a surface; frequency rank 656831
- homozygote — an organism or cell with two identical alleles at a specified genetic locus; frequency rank 679184
- pangenesis — Darwin's disproved hypothesis that every part of an organism releases hereditary particles which collect in reproductive cells and can be passed to offspring; frequency rank 687105
- electrolyze — to decompose by means of, or as a result of electrolysis.; frequency rank 738019
- gemmule — a small asexual reproductive bud or resistant cluster of cells, especially one produced by a sponge or another simple organism; frequency rank 818645
- cilium — a microscopic hairlike projection from a eukaryotic cell, used for movement, moving fluid, or sensing the environment; frequency rank 833200
- diffract — of a wave or particle beam, to spread or change direction through interference after meeting an edge, aperture, or periodic structure; frequency rank 945159
- congelation — the process or result of congealing, especially changing from a liquid to a solid by cooling; frequency rank 949605
- trituration — the act or process of crushing, rubbing, or grinding a substance into fine particles; frequency rank 961897
- rarefy — to make a gas thinner or less dense; frequency rank 1075665
- conchological — relating to conchology, the scientific study and classification of mollusc shells; frequency rank 1100960
- fossiliferous — bearing or containing fossils; frequency rank 1185640
- verifiability — the quality of being capable of being checked or confirmed by evidence, observation, or a specified procedure; frequency rank 1236813
- antineutron — the antiparticle of the neutron, with the same mass and no net electric charge but opposite baryon number; frequency rank 1249088
- consilience — agreement between conclusions reached independently from different kinds of evidence; frequency rank 1250208
- volatilize — to cause a substance to become vapor, or to pass off as vapor; frequency rank 1254069
- mongrelize — to crossbreed plants or animals so that their offspring have mixed ancestry; frequency rank 1331404
- deliquesce — to absorb moisture from the air until dissolved in the resulting liquid; frequency rank 1345794
- agglutinate — to cause particles, cells, or other separate things to stick together in a clump or mass, or to undergo such clumping; frequency rank 1368599
- precessional — relating to precession, the slow change in the orientation of a rotating body's axis or orbit; frequency rank 1389295
- counterfactual — relating to or expressing what has not happened but could happen under different conditions
- intercrossing — The interbreeding of two strains that have a common ancestry
- classificatory — relating to or involving classification:'classificatory criteria'
- aestivation — (botany) the arrangement of sepals and petals in a flower bud before it opens
- light-wave — a wave of electromagnetic radiation considered as light
- light-ray — a line or narrow beam representing the path along which light travels
- light-quantum — a quantum of light; a photon
- timelike — relating to a spacetime interval that can connect events by a signal slower than light
- spacelike — relating to a spacetime interval whose endpoints cannot be connected by a light-speed or slower signal
- spatiotemporal — relating to both space and time
- reversibility — the quality of being able to be reversed
- world-line — the path of an object through spacetime
- undulatory — moving in waves or relating to wave motion
- stratify — to form, arrange, or deposit something in distinct layers
- intercross — biology and genetics: to breed individuals from two strains or populations
- systematist — a biologist who studies systematics and classifies organisms by their relationships
- congener — a person or thing of the same kind or class as another
- vivisector — a person who performs vivisection or experiments involving operations on living animals
- uranyl — the linear dioxouranium(VI) cation UO2^2+, a common structural unit in uranium(VI) compounds and complexes
- nonscience — a subject, practice, or body of claims that is not science or does not use scientific methods
- peptone — a water-soluble mixture of peptides and amino acids produced by the partial hydrolysis of protein
- photomicrograph — a photograph made through a microscope so that a highly magnified subject can be recorded
- polyploidy — the condition or process of having more than two complete sets of chromosomes in a cell or organism
- radiational — relating to, involving, or caused by radiation
- infecundity — inability or reduced ability to reproduce; lack of fertility
- pre-Copernican — existing before Nicolaus Copernicus's work or before acceptance of the heliocentric model associated with him
- telegony — historical genetics: the discredited belief that a female's previous mate can influence offspring later conceived with another mate
- prepotency — an unusual ability of one parent, individual, or strain to transmit its characteristics strongly to offspring
- azoic — containing no evidence of life or dating from a time believed to precede life
- baryta — an older chemical name for barium oxide, or more broadly for certain barium compounds such as barium hydroxide
- bisulfate — the hydrogen sulfate ion, HSO4-, which is formed when sulfuric acid loses one proton
- homologize — to identify or demonstrate that structures in different organisms correspond because of shared evolutionary origin
- serrature — a row or arrangement of sawlike notches or teeth along an edge
- deliquescent — chemistry: absorbing enough moisture from the air to dissolve gradually and form a solution
- infusorial — historical biology: relating to, containing, or formed from Infusoria, a former broad grouping of microscopic aquatic organisms
- iodic — relating to iodine, especially to compounds in which iodine has oxidation state +5, such as iodic acid and iodates
- parenchymatous — consisting of, relating to, or affecting parenchyma, the functional or softer tissue of an organ
- exsert — to thrust, extend, or cause a body part or structure to project outward
- terraqueous — consisting of both land and water, especially in the phrase terraqueous globe for Earth
- spiculum — biology: a small sharp needle-like structure, especially a skeletal element of a sponge or other invertebrate
- homolog — a biological structure, organ, gene, or other feature that shares a common evolutionary origin with a corresponding feature
- rugosity — the quality or degree of being rough, wrinkled, or ridged
- pectinate — biology: shaped or arranged like the teeth of a comb
- pilus — A hair.
- hypophosphite — Any salt of hypophosphorous acid
- vitalism — a historical theory that living things depend on a special vital force beyond ordinary physical and chemical processes

### C2+
- poker — One who pokes.; frequency rank 4211
- slate — designate or schedule; frequency rank 10093
- malignant — Harmful, malevolent, injurious.; frequency rank 18761
- extort — obtain by coercion or intimidation; frequency rank 25581
- causeway — to provide with a causeway; frequency rank 30322
- unattainable — impossible to achieve; frequency rank 33538
- infrasound — sound waves having a frequency below the human audible range (below about 20 Hz).; frequency rank 78000
- well-nigh — Almost, nearly.; frequency rank 129740
- fulgurite — a glassy, often branching tube or crust formed when lightning fuses sand, soil, or rock; frequency rank 160349
- antihydrogen — the antimatter counterpart of hydrogen, whose atom consists of a positron bound to an antiproton; frequency rank 252684
- arachnologist — a scientist who specializes in the study of spiders and other arachnids; frequency rank 390140
- fecundate — formal: to make an organism, egg, or reproductive structure fertile; to fertilize or impregnate; frequency rank 410279
- germplasm — the hereditary material of a species or breeding line, especially as transmitted through reproductive cells; frequency rank 622684
- mu-meson — dated, the former name for the muon, used when that particle was mistakenly classified as a meson rather than a lepton; frequency rank 672335
- pi-meson — a pion, any of three unstable spin-zero mesons with positive, negative, or zero charge, formed from combinations of up and down quarks and antiquarks; frequency rank 672349
- interplanetarian — relating to travel, communication, or events between planets; interplanetary; frequency rank 1413987
- ebullient — cheerful and full of energy; exuberant
- languid — displaying a pleasant lack of energy or a relaxed slowness
- notional — existing only in theory or as a supposition; hypothetical
- obligate — to bind legally or morally; in biology, restricted to one mode of life
- sluggish — slow-moving, inactive, or lacking energy
- enervate — to weaken or drain of energy, strength, or vitality
- lackadaisical — lacking enthusiasm, energy, or determination
- torpid — sluggish, inactive, or mentally dull; lacking energy
- analytic — relating to or proceeding by analysis; logically rigorous
- doctrinaire — rigidly adhering to a theory or doctrine regardless of practicality
- empiric — one who relies on observation or experiment; an unqualified practitioner
- invigorate — to give strength, energy, or fresh vitality to
- mutation — a change in form or structure, especially a heritable change in genetic material
- rudiment — a basic principle or element, or an undeveloped beginning of something
- zeal — great energy or enthusiasm in pursuit of a cause or objective
- alchemy — the medieval forerunner of chemistry seeking to transmute metals into gold
- axiomatization — the formulation of a theory as a set of axioms from which theorems derive
- behaviorism — the psychological theory that behavior can be explained by conditioning
- counterpoint — a contrasting element set against another; combined melodic lines
- evolutional — of or relating to evolution or gradual development
- feeler — an antenna or tentacle, or a tentative proposal to test reaction
- formulaic — following a set formula; predictable and unoriginal
- frisky — lively, playful, and full of energy
- inhibitor — a substance or agent that slows or prevents a reaction or process
- invigoration — the act of giving strength, energy, or fresh vitality
- kilocalorie — a unit of energy equal to one thousand calories
- kiteflying — the flying of kites; also the floating of a rumor to test reaction
- nonempirical — not based on observation or experiment
- nonexciting — not exciting; dull or, in physics, not causing excitation
- radiative — relating to or transferring energy by radiation
- revisionist — one who advocates revising an accepted theory, doctrine, or history
- sluggishness — the state of being slow, dull, or lacking energy
- smeddum — spirited energy, mettle, or resourcefulness (Scots dialect)
- strenuous — requiring or using great effort or energy
- theorize — to form a theory or speculate about something
- virile — having strength, energy, or qualities regarded as masculine
- inosculation — a natural or surgical joining of parts or branches of tubular structures so as to make or become continuous
- experimentise — To experiment.
- infusorium — a microscopic aquatic organism, especially a protozoan or unicellular alga, formerly grouped with organisms found in infusions; historical biology
- cetology — the branch of zoology concerned with cetaceans, including whales, dolphins, and porpoises
- antigalaxy — a hypothetical galaxy composed predominantly of antimatter rather than ordinary matter
- antideuteron — the antiparticle of a deuteron, consisting of an antiproton bound to an antineutron
- heterozygousness — the condition or quality of having two different alleles at a particular genetic locus
- prenewtonian — existing before Isaac Newton's work or before the adoption of Newtonian science
- pithecanthropus — the former genus Pithecanthropus, especially the Javan fossil hominins now generally classified as Homo erectus
- cosmogonal — relating to cosmogony or to a theory about the origin and development of the universe
- osculant — intermediate between two taxonomic groups and sharing characteristics of each
- carbonic acid — a weak acid, H2CO3, formed when carbon dioxide dissolves in water
- cosmogonist — a person who studies the origin and development of the universe or proposes a theory about it
- nonconductivity — the property or condition of not transmitting heat, electricity, sound, or another form of energy
- aeriform — having the nature or physical form of air; gaseous
- patelliform — shaped like a shallow dish or a limpet shell
- silicify — to convert material into silica or impregnate it with silica, especially during fossilization or rock alteration
- labiate — biology: having lips or lip-like parts, especially a flower whose corolla is divided into two lips
- argillocalcareous — geology and soil science: consisting of or containing both clay and calcareous material such as calcium carbonate
- sporule — rare or historical biology: a small spore, especially one produced by a cryptogam or microorganism
- cancellate — formed like an open lattice or network, especially of intersecting bars, plates, or bony struts