An oxymoron (usual plural oxymorons, less commonly the Greek-style oxymora) is a figure of speech that juxtaposes elements that appear to be contradictory, but which contain a concealed point. Oxymorons appear in a variety of contexts, including inadvertent errors (such as "ground pilot") and literary oxymorons crafted to reveal a paradox.
The most common form of oxymoron involves an adjective–noun combination of two words. For example, the following line from Tennyson's Idylls of the King contains two oxymorons:
And faith unfaithful kept him falsely true.
Oxymorons are not always a pair of words; they can also be devised in the meaning of sentences or phrases.
Oxymoron is derived from the 5th century Latin: oxymorus, oxymōrus, which is derived from the Ancient Greek: ὀξύς oksús "sharp, keen, pointed" and μωρός mōros "dull, stupid, foolish", making the word itself an oxymoron. However, the combined Greek form ὀξύμωρον (oksúmōron) does not in fact appear in the extant Greek sources.
Richard Lederer assembled a taxonomy of oxymorons in an article in Word Ways in 1990, running from single-word oxymorons such as "pianoforte" (literally, "soft-loud") through "doublespeak oxymorons" (deliberately intended to confuse) and "opinion oxymorons" (editorial opinions designed to provoke a laugh). In general, oxymorons can be divided into expressions that were deliberately crafted to be contradictory and those phrases that inadvertently or incidentally contain a contradiction, often as a result of a punning use of one or both words.