malaprop

/ˈmæləprɑp/
noun
  1. A humorous misuse of a word that sounds similar to the intended word, often creating a ridiculous effect.
    • The character in the play was famous for his malaprops, like calling a 'monopoly' a 'monotony.'
    • My grandfather's malaprop turned 'allegory' into 'alligator,' which became a family joke.
    • When she said 'dance a flamingo' instead of 'dance a flamenco,' everyone laughed at the malaprop.
Synonyms
verb
  1. To use a word incorrectly by substituting a similar-sounding word, usually with a humorous result.
    • She malapropped 'exasperate' for 'accelerate' during the driving test.
    • He tends to malaprop when he's nervous, saying things like 'I have a photographic memory for faces.'
    • The comedian malapropped on purpose to get laughs from the audience.