An oxymoron (plurals: oxymorons and oxymora) is a figure of speech that juxtaposes concepts with opposite meanings within a word or in a phrase that is a self-contradiction. As a rhetorical device, an oxymoron illustrates a point to communicate and reveal a paradox. A general meaning of "contradiction in terms" is recorded by the 1902 edition of the Oxford English Dictionary.

The term oxymoron is first recorded as Latinized Greek oxymōrum, in Maurus Servius Honoratus (c. AD 400); it is derived from the Greek word ὀξύς oksús "sharp, keen, pointed" and μωρός mōros "dull, stupid, foolish"; as it were, "sharp-dull", "keenly stupid", or "pointedly foolish". The word oxymoron is autological, i.e. it is itself an example of an oxymoron. The Greek compound word ὀξύμωρον oksýmōron, which would correspond to the Latin formation, does not seem to appear in any known Ancient Greek works prior to the formation of the Latin term.