imaginary

Meanings

1. 1
   adj

   Existing only in the imagination.

   imaginary friend

2. 2
   noun

   Imagination; fancy.

   By then too Mozart's opera, from Da Ponte's libretto, had made Figaro a stock character in the European imaginary and set the whole Continent whistling Mozartian airs and chuckling at Figaresque humour.

3. 3
   noun

   The set of values, institutions, laws, and symbols common to a particular social group and the corresponding society through which people imagine their social whole.

   The sensory media are sensuous materials which prolong our bodily life into the surrounding world, and hence the media are imaginaries. These perceptually penetrated materials are " imaginaries " because they operate here in our living body […].

4. 4
   adj

   not based on fact

5. 5
   noun

   (mathematics) a number of the form a+bi where a and b are real numbers and i is the square root of -1

6. 6
   adj

   Having no real part; that part of a complex number which is a multiple of √ (called imaginary unit).

7. 7
   noun

   An imaginary number.

Etymology

From Middle English ymaginarie, ymagynary, from Latin imāginārius (“relating to images, fancied”), from imāgō, equivalent to imagine + -ary. The mathematical sense derives from René Descartes's use (of the French imaginaire) in 1637, La Geometrie, to ridicule the notion of regarding non-real roots of polynomials as numbers. Although Descartes' usage was derogatory, the designation stuck even after the concept gained acceptance in the 18th century.