A word that has the opposite meaning of another word. Used in linguistic contexts and everyday explanations.
The antonym of 'big' is 'small'.
A dictionary is useful when looking up antonyms.
反対語 is a more general term for 'opposite word' and is often used interchangeably with 対義語 in everyday speech, though 対義語 is more technical.
対義語 means a word opposite in meaning, the direct opposite of 同義語 (a word with the same meaning).
From 対 (opposite) + 義 (meaning) + 語 (word). A straightforward compound that transparently means 'opposite-meaning word'.