Some meanings stand in direct opposition. An antonym is a word whose meaning is contrary or complementary to that of another word, such as hot and cold or buy and sell.

Lexical semantics distinguishes gradable antonyms, which allow intermediate degrees, from complementary pairs that admit no middle ground, and from relational opposites that describe reciprocal roles. Dictionaries and thesauruses list antonyms to support precise word choice and vocabulary learning.

Not every word has a neat opposite, and cultural factors can shape which contrasts feel natural. Antonymy helps structure semantic fields and supports rhetorical devices that rely on contrast. Children acquire many common antonym pairs early as they organize experience into opposing categories.

• Word with a contrary or opposite meaning
• Includes gradable, complementary, and relational types
• Used in dictionaries and vocabulary teaching
• Helps organize semantic fields through contrast