existing only in the imagination or fancy; not real; fancied: an imaginary illness; the imaginary animals in the stories of Dr. Seuss.

noun, plural im·ag·i·nar·ies.

Mathematics. imaginary number.

Origin of imaginary

1350–1400; Middle English < Latin imāginārius, equivalent to imāgin-, (stem of imāgō) image + -ārius -ary
Related formsim·ag·i·nar·i·ly, adverbim·ag·i·nar·i·ness, nounnon·im·ag·i·nar·i·ly, adverbnon·im·ag·i·nar·i·ly·ness, nounnon·im·ag·i·nar·i·ness, nounnon·im·ag·i·nar·y, adjectivepre·im·ag·i·nar·y, adjectiveun·im·ag·i·nar·y, adjective
Can be confusedimaginary imaginative

Synonyms for imaginary

Antonyms for imaginary

1. real. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for unimaginary



existing in the imagination; unreal; illusory
maths involving or containing imaginary numbers. The imaginary part of a complex number, z, is usually written Im z
Derived Formsimaginarily, adverbimaginariness, noun
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for unimaginary



"not real," late 14c., ymaginaire, from imagine + -ary; or else from Late Latin imaginarius "seeming, fancied," from imaginari. Imaginary friend (one who does not exist) attested by 1789.

Online Etymology Dictionary, © 2010 Douglas Harper