This week on The Missing Workbook
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Word
English Vocabulary
Pick a CEFR level (A1–C2, plus C2+ for rare words beyond the CEFR scale) — A1 is the friendliest place to start — and browse its words grouped by topic: travel, food, the body, emotions, and more. Each word shows its meaning, example sentences, and US/UK pronunciation.
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View all levelsC2+ is beyond the official CEFR scale: rare, specialist, and literary words kept for reference.
61 words
mutant
C2
/ˈmjuː.tənt/
an organism, cell, gene, or other biological entity that carries a mutation
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hypothesis
C2
[haɪˈpʰɑθəsɪs]
An idea put forward to explain something, which can then be tested.
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arsenic
C2
/ˈɑɹsənɪk/
a very poisonous metallic element that has three allotropic forms
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plutonium
C2
/pluːˈtoʊniəm/
The transuranic chemical element with atomic number 94 and symbol Pu: a silvery-gray fissile radioactive actinide metal that tarnishes when exposed to air.
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brimstone
C2
/ˈbɹɪmstoʊn/
An old name for the element sulfur.
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iridium
C2
/ɪˈɹɪd.i.əm/
a chemical element (symbol Ir) with an atomic number of 77: a very hard, brittle, silvery-white transition metal of the platinum group.
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argon
C2
/ˈɑːr.ɡɑːn/
the chemical element with symbol Ar and atomic number 18, a colorless, odorless, largely unreactive noble gas that forms about 0.93 percent of Earth's atmosphere
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amoeba
C2
/əˈmiː.bə/
a single-celled organism that changes shape and moves or feeds by extending pseudopodia
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fluoride
C2
/ˈflɔːr.aɪd/
a compound in which fluorine is combined with a more electropositive element or chemical group
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hermaphrodite
C2
/hɝˈmæfɹədaɪt/
Cosexual: an organism possessing both types of gonads; a flower possessing both stamens and pistils.
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graviton
C2
/ˈɡræv.ɪˌtɑːn/
a hypothetical massless spin-2 boson that would be the quantum carrier of gravity in a quantum theory of the gravitational field
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quicksilver
C2
/ˈkwɪkˌsɪlvɚ/
the metallic element mercury, especially when seen in its mobile liquid form
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jurisprudence
C2
/ˌdʒʊr.ɪsˈpruː.dəns/
the theory or philosophy of law and the principles by which legal systems interpret and apply it
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beryllium
C2
/bəˈrɪl.i.əm/
the chemical element with symbol Be and atomic number 4, a hard, gray, low-density alkaline-earth metal valued for its stiffness and transparency to X-rays
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metallurgy
C2
/ˈmɛt.əˌlɝ.dʒi/
the science and technology of extracting metals, refining and alloying them, and controlling their properties during processing
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ism
C2
/ˈɪz.əm/
a distinctive doctrine, theory, cause, or movement, especially one named with the suffix -ism
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fluorine
C2
/ˈflɔːr.iːn/
the chemical element with symbol F and atomic number 9, whose elemental form is an extremely reactive, toxic, pale-yellow halogen gas
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thorium
C2
/ˈθɔːɹiəm/
a soft silvery-white tetravalent radioactive metallic element
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jurist
C2
/ˈdʒʊr.ɪst/
an expert or scholar in law and legal theory
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silicate
C2
/ˈsɪlɪkət/
chemistry: a salt or ester derived from a silicic acid and containing silicon and oxygen
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bismuth
C2
/ˈbɪz.məθ/
the chemical element with symbol Bi and atomic number 83, a dense, brittle, crystalline metal that is silvery white with a pink tinge
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vanadium
C2
/vəˈneɪ.di.əm/
the chemical element with symbol V and atomic number 23, a silvery transition metal used chiefly to strengthen steel and in several industrial catalysts
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bromine
C2
/ˈbroʊ.miːn/
the chemical element with atomic number 35 and symbol Br, a toxic, fuming red-brown halogen that is liquid at room temperature
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promethium
C2
/prəˈmiː.θi.əm/
the radioactive rare-earth chemical element with symbol Pm and atomic number 61, which has no stable isotopes
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atavism
C2
/ˈætəˌvɪzəm/
the reappearance in an organism of a trait associated with a remote ancestor
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utilitarianism
C2
/ˌjuːtɪlɪˈteriənɪzəm/
the ethical theory that the best action is the one that produces the greatest overall well-being or happiness
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epistemology
C2
/ɪˌpɪstəˈmɑləd͡ʒi/
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.
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radioisotope
C2
/ˌreɪ.di.oʊˈaɪ.sə.toʊp/
a radioactive isotope of an element, whose unstable nuclei decay and emit radiation
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actinium
C2
/ækˈtɪn.i.əm/
the radioactive metallic chemical element with symbol Ac and atomic number 89, the first element of the actinide series
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agriculturist
C2
/ˌæɡrɪˈkʌltʃərɪst/
a specialist trained in the science, practice, or management of agriculture
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embryology
C2
/ˌɛmbriːˈɑːlədʒi/
the branch of biology that studies the formation and early development of living organisms
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sensorium
C2
/sɛnˈsoɹ.i.jəm/
The entire sensory apparatus of an organism.
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technetium
C2
/tɛkˈniː.ʃi.əm/
the radioactive metallic chemical element with symbol Tc and atomic number 43, all of whose isotopes are unstable
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vesicle
C2
/ˈvɛsɪkəl/
a small membrane-bound sac or cavity in a cell or organism, often containing fluid or another substance
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plasm
C2
/ˈplæzəm/
biology, now rare: the living substance of a cell; protoplasm
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neptunium
C2
/nɛpˈtjuːniəm/
the radioactive transuranic chemical element with symbol Np and atomic number 93
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hermaphroditism
C2
/hɚˈmæfɹədaɪˌtɪzəm/
in biology, the condition of having both male and female reproductive organs, either simultaneously or at different life stages
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protactinium
C2
/ˌproʊ.tækˈtɪn.i.əm/
the chemical element with symbol Pa and atomic number 91, a dense, silvery, highly radioactive actinide metal with no stable isotopes
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integument
C2
/ˌɪnˈtɛɡ.jə.mənt/
a natural outer covering that protects an organism or one of its parts, such as skin, a shell, or a seed coat
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curium
C2
/ˈkjʊə.ɹi.əm/
a synthetic radioactive metallic chemical element with atomic number 96 and symbol Cm
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dietetics
C2
/ˌdaɪəˈtɛtɪks/
the science and professional practice of planning diets in relation to health and disease
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sequent
C2
/ˈsiː.kwənt/
in proof theory, a formal expression showing that one or more conclusion formulas follow from a collection of premise formulas
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fermium
C2
/ˈfɜːɹmiəm/
a synthetic radioactive chemical element with atomic number 100 and symbol Fm
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filum
C2
/ˈfaɪləm/
anatomy and biology: a slender thread-like structure or filament
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protozoon
C2
/ˌproʊtəˈzoʊɑn/
dated: a single protozoan organism; one of the mostly microscopic unicellular organisms formerly grouped as Protozoa
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conversazione
C2
/ˌkɑnvɚsɑtsiˈoʊni/
a formal social gathering devoted to discussion of literature, art, science, or another learned subject
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lawrencium
C2
/ləˈɹɛnsiəm/
a synthetic radioactive chemical element with atomic number 103 and symbol Lr
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heterozygote
C2
/ˌhet̬.ə.roʊˈzaɪ.ɡoʊt/
an organism or cell having two different alleles at a particular gene locus
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homozygote
C2
/ˌhoʊmoʊˈzaɪɡoʊt/
an organism or cell with two identical alleles at a specified genetic locus
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pangenesis
C2
/ˌpænˈdʒɛnəsɪs/
Darwin's disproved hypothesis that every part of an organism releases hereditary particles which collect in reproductive cells and can be passed to offspring
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monadology
C2
/ˌmɑnəˈdɑlədʒi/
a metaphysical doctrine or study of monads, especially Leibniz's theory that reality consists of simple immaterial substances
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contravariance
C2
/ˌkɑntrəˈvɛriəns/
opposite-direction variation or transformation, especially in tensors, category theory, or type systems
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timocracy
C2
/tɪˈmɑkrəsi/
in Plato's political theory, a form of government ruled by people motivated chiefly by honor and military glory
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visiplate
C2
/ˈvɪz.iˌpleɪt/
in science fiction, an electronic screen capable of displaying images or data
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scientifiction
C2
/ˌsaɪ.ən.tɪˈfɪk.ʃən/
dated: science fiction, especially fiction that combines scientific facts or speculation with adventure and predictions about the future
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copperas
C2
/ˈkɑːpərəs/
historical chemistry: iron(II) sulfate, a green crystalline compound used in dyes, inks, tanning, and other processes
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tetrachord
C2
/ˈtɛtɹəˌkɔɹd/
in music theory, a series of four notes spanning the interval of a perfect fourth
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sesquialtera
C2
/sɛskwɪˈaltərə/
in mathematics or musical theory, the ratio 3:2, in which one quantity is one and a half times another
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connexity
C2
/kəˈnɛk.sə.ti/
in logic and order theory, the property of a relation whereby any two distinct relevant terms are related in one direction or the other
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spiculum
C2
/ˈspɪkjʊləm/
biology: a small sharp needle-like structure, especially a skeletal element of a sponge or other invertebrate
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vitalism
C2
/ˈvaɪtəˌlɪzəm/
a historical theory that living things depend on a special vital force beyond ordinary physical and chemical processes
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