a figure of speech by which a locution produces an incongruous, seemingly self-contradictory effect, as in “cruel kindness” or “to make haste slowly.”
Origin: 1650–60; < Late Latinoxymorum < presumed Greek*oxýmōron, neuter of *oxýmōros sharp-dull, equivalent to oxý(s) sharp (see oxy-1) + mōrós dull (see moron)
1657, from Gk. oxymoron, noun use of neut. of oxymoros (adj.) "pointedly foolish," from oxys "sharp" (see acrid) + moros "stupid." Rhetorical figure by which contradictory terms are conjoined so as to give point to the statement or expression; the word itself is an illustration
of the thing. Now often used loosely to mean "contradiction in terms."