from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A word having a meaning opposite to that of another word: The word wet is an antonym of the word dry.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A word which has the opposite meaning of another, although not necessarily in all its senses.
from the GNU version of the Collaborative International Dictionary of English
- n. A word of opposite meaning; a counterterm; -- used as a correlative of synonym.
from The Century Dictionary and Cyclopedia
- n. A counterterm; an opposite; an antithetical word: the opposite of synonym: as, life is the antonym of death.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. a word that expresses a meaning opposed to the meaning of another word, in which case the two words are antonyms of each other
ant(i)- + -onym.(American Heritage® Dictionary of the English Language, Fourth Edition)
circa 1870: ant- + -onym (Wiktionary)