- a word opposite in meaning to another. Fast is an antonym of slow.Compare .
- a word that means the opposite of another word“empty” is an antonym of “full”
1867, coined to serve as opposite of anti- “equal to, instead of, opposite” (see ) + -onym “name” (see (n.)). Perhaps introduced to English in the book “Synonyms and Antonyms” (1867) by the Ven. C.J. Smith, M.A., from Greek
UNDER the head of Synonyms and Antonyms, Archdeacon Smith arranges words which form an antithesis to one another. The word “antonym” is, we believe, a new formation but useful. [“Journal of Sacred Literature,” July 1867]
French antonyme (1842), German antonym (by 1859) are older. The un-Greek alternative counterterm has been left to fade.