imaginary

== English == === 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. === Pronunciation === (Received Pronunciation) IPA(key): /ɪˈmæd͡ʒɪnəɹi/, /ɪˈmæd͡ʒɪnɹi/ (General American) IPA(key): /ɪˈmæd͡ʒɪˌn(ɛ)ɹi/ Hyphenation: im‧a‧gin‧a‧ry === Adjective === imaginary (comparative more imaginary, superlative most imaginary) Existing only in the imagination. imaginary friend (mathematics, of a number) Having no real part; that part of a complex number which is a multiple of − 1 {\displaystyle {\sqrt {-1}}} (called imaginary unit). ==== Synonyms ==== (existing only in the imagination): all in one's head ==== Derived terms ==== ==== Translations ==== === Noun === imaginary (plural imaginaries) Imagination; fancy. [from 16th c.] (mathematics, countable) An imaginary number. [from 18th c.] (sociology) 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. [from c. 1975] === References ===