antonym

n. word having the opposite meaning of another word

Antonyms, from the Greek anti ("opposite") and onoma ("name") are word pairs that are opposite in meaning, such as hot and cold, obese and skinny, and up and down. Words may have different antonyms, depending on the meaning. Both long and tall are antonyms of short. Antonyms are of four types:Gradable antonyms are two ends of the spectrum (slow and fast) but can have variations.Complementary antonyms are pairs that express absolute opposites, like mortal and immortal.Relational antonyms are pairs in which one describes a relationship between two objects and the other describes the same relationship when the two objects are reversed, such as parent and child, teacher and student, or buy and sell.Auto-antonyms are the same words that can mean the opposite of themselves under different contexts or having separate definitions enjoin (to prohibit, issue injunction; to order, command) (moving quickly; fixed in place) (to ; to ) (punishment, prohibition ;  permission)stay ( in a specific place, postpone; direction, movement)
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Noun
1. two words that express opposing concepts; "to him the opposite of gay was depressed"
(synonym) opposite word, opposite
(hypernym) word
(hyponym) direct antonym

n. antonym, word having the opposite meaning of another word

adj. antonymous, pertaining to an antonym

(n.)
A word of opposite meaning; a counterterm; -- used as a correlative of synonym.