malapropism

 
Pronunciation: /ˈmaləprɒˌpɪz(ə)m/
(US also malaprop)

noun

  • the mistaken use of a word in place of a similar-sounding one, often with an amusing effect (e.g. ‘dance a flamingo’ instead of flamenco).

Origin:

mid 19th century: from the name of the character Mrs Malaprop in Sheridan's play The Rivals (1775) + -ism