Oxymoron Definition

ŏksē-môrŏn

oxymora, oxymorons

noun

A figure of speech in which opposite or contradictory ideas or terms are combined (Ex.: thunderous silence, sweet sorrow)

Webster's New World

A figure of speech in which two words with opposing meanings are used together intentionally for effect.

Wiktionary

(general) A contradiction in terms.

Wiktionary

Other Word Forms of Oxymoron

Singular:

oxymoron

Plural:

oxymorons

First attested in the 17th century, noun use of 5th century Latin oxymōrum (adj), neut. nom. form of oxymōrus (adj), from Ancient Greek ὀξύμωρος (oxumōros), compound of ὀξύς (oxus, “sharp, keen") (English oxy-, as in oxygen) + μωρός (mōros, “dull, stupid") (English moron (“stupid person")). Literally “sharp-dull" or "keen-stupid", itself an oxymoron, hence autological; compare sophomore (literally “wise fool"), influenced by similar analysis. The compound form *ὀξύμωρον (oxumōron) is not found in the extant Ancient Greek sources.

From Wiktionary
Greek oxumōron an expression that is witty because paradoxical from neuter of oxumōros pointedly foolish oxus sharp, keen oxygen mōros dull, foolish

From American Heritage Dictionary of the English Language, 5th Edition