Malapropism - the act or habit of misusing words to comic effect. This usually results from ignorance or from confusion of words similar in sound but different in meaning, mainly polysyllabic words.
The term is taken directly from the French mal a propos, meaning “inappropriate.”
Mrs. Malaprop is a character in Sheridan’s play The Rivals (1775) who chronically makes such mistakes. Dogberry the Watch in Shakespeare’s Much Ado About Nothing (c. 1598) says “Comparisons are odorous,” and later, “It shall be siffigance”—both malapropisms.
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