Malaprop, Mrs., is a character in the Irish dramatist Richard Brinsley Sheridan’s comedy The Rivals (1775). Sheridan took the name from the French phrase mal a propos, meaning out of place or inappropriate. Mrs. Malaprop constantly misuses words, as in this example:
But the point we would request of you is, that you will promise to forget this fellow—to illiterate him, I say, quite out of your memory.
Malapropism has come to mean the ludicrous or amusing misuse of words.