Contradictio in terminis

A contradictio in terminis (Latin: contradiction in terms) is a certain connection between two words in a group out of which it can be derived that such a combination is entirely impossible. Examples are "liquid ice" or "square circle".

The term is also used for politically incorrect humor. "Incomplex woman" or "military intelligence" are examples of contradictiones in terminis used for this purpose.

However, if the contradiction is intentional (rhetorical or poetic), then one can speak of an oxymoron.