antonym has 2 distinct synonyms spread across 1 of its 1 sense. Each sense below keeps its own list, because a synonym belongs to a meaning and not to a word: swapping one sense's substitute into another sense's sentence is how a thesaurus makes writing worse. Its one recorded opposite is synonym.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
a word that expresses a meaning opposed to the meaning of another word, in which case the two words are antonyms of each other
“to him the antonym of `gay' was `depressed'”
Synonyms, antonyms and the broader and narrower relations for antonym come from Princeton University’s WordNet. Full sources and licences.