noun Rhetoric.
- the use of a word in a sense opposite to its proper meaning.
noun
- rhetoric the use of a word in a sense opposite to its normal one, esp for ironic effect
1530s, from Latin antiphrasis, from Greek antiphrasis, from antiphrazein “to express (something) by the opposite,” from anti- (see anti-) + phrazein “to consider, to express” (see phrase (n.)).