Oxymoron

An oxymoron ("oxim-oron", not "oxy-moron") is a phrase in which the meaning of one part is in diametric opposition to the meaning of another part. The political ideology of modern American conservatism is replete with oxymorons. Oxymorons can be nonsense such as "cold heat", "dry water", "optimistic pessimist", but they are often used in figures of speech including "found missing", "same difference", "terribly good", "genuine fake", "passive aggressive" and so on.

Usage
Despite, or perhaps because of the obvious contradictions, oxymorons can be used deliberately in both comedy and politics to elicit a desired response in the audience. George Carlin has indeed popularized some oxymorons for comedic effect such as "military intelligence" and "business ethics".