from The American Heritage® Dictionary of the English Language, 4th Edition
- adj. Having existence only in the imagination; unreal.
- adj. Mathematics Of or being the coefficient of the imaginary unit in a complex number.
- adj. Mathematics Of, involving, or being an imaginary number.
- adj. Mathematics Involving only a complex number of which the real part is zero.
- n. Mathematics An imaginary number.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. existing only in the imagination
- adj. of a number, having no real part; that part of a complex number which is a multiple of the square root of -1.
from the GNU version of the Collaborative International Dictionary of English
- adj. Existing only in imagination or fancy; not real; fancied; visionary; ideal.
- n. An imaginary expression or quantity.
from The Century Dictionary and Cyclopedia
- Existing only in imagination or fancy; due to erroneous belief or conception; not real; baseless; fancied: opposed to actual.
- In mathematics, unreal and feigned in accordance with the theory of imaginary quantities.
- Synonyms Ideal, fanciful, fancied, visionary, unreal, shadowy, Utopian. Imaginary and imaginative are never synonymous: imaginary means existing only in the imagination; imaginative means possessed of or showing an active imagination.
- n. In algebra, an imaginary expression or quantity.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- adj. not based on fact; unreal
- n. (mathematics) a number of the form a+bi where a and b are real numbers and i is the square root of -1
From Latin imāginārius ("relating to images, fancied"), from imāgo. (Wiktionary)