/ Dictionary / Index A antonym: Meaning and Definition of Find definitions for: an•to•nym Pronunciation: (an'tu-nim), [key] — n. a word opposite in meaning to another. Fast is an antonym of slow. Cf. synonym (def. 1). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: antonym (Thesaurus) Antony and Cleopatra* ant-pipit Related Content Daily Word Quiz: deleterious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language