Malapropism

['mæləprɒ,pɪz(ə)m] or ['mæləprɑpɪzəm]

(noun.) the unintentional misuse of a word by confusion with one that sounds similar.

Edited by Jonathan--From WordNet

(n.) A grotesque misuse of a word; a word so used.

Edited by Charlene

n. the act of misapplying words in the attempt to use fine language from Mrs Malaprop in Sheridan's play The Rivals.

Edited by Horace