A malapropism is the misuse of a word, usually unintentionally, involving replacing the intended word with a similar sounding word with a very different meaning. Oftentimes, the incorrectly used word is humorous. Malapropisms can also be referred to as Dogberryisms.
Malapropism comes from the French phrase mal à propos, which means “ill-suited.” Malapropos is an adjective meaning inappropriate. The word malapropism was coined in Richard Brinsley Sheridan’s The Rivals, 1775, from the character Ms. Malaprop.
Conversely, Dogberryism came into the English language in 1598, in Shakespeare’s Much Ado About Nothing, where the character Dogberry uses many words incorrectly. Both Shakespeare’s and Sheridan’s works show exactly how humorous malapropisms can be.
Famous examples of malapropisms:
“Alcoholics Unanimous” (to refer to Alcoholics Anonymous) - Mayor Richard Daley
“Our watch, sir, have indeed comprehended two auspicious persons.” (to mean apprehended two suspicious persons) - Constable Dogberry, Much Ado About Nothing
"The law I sign today directs new funds... to the task of collecting vital intelligence... on weapons of mass production." (to mean mass destruction) - George W. Bush
"Half the lies they tell about me aren't true." - Yogi Berra
"He is the very pineapple of politeness." (pinnacle of politeness) - Ms. Malaprop, The Rivals
“Republicans understand the importance of bondage between a mother and child.” – Dan Quayle, former Vice President
“A rolling stone gathers no moths.” - Unknown