Pun

A pun, "also known as a paronomasia," is "a form of word play that exploits multiple meanings of a term," done "for an intended humorous or rhetorical effect." The article sorts the mechanism: a homophonic pun "uses word pairs which sound alike (homophones) but are not synonymous," a homographic one "exploits words that are spelled the same (homographs) but possess different meanings and sounds," and homonymic puns do both at once. The habit is old: Plautus was "famous for his puns and word games," "punning was used by scribes to represent words in cuneiform" around 2500 BC, and Shakespeare is "estimated to have used over 3,000 puns in his plays," Mercutio dying on "Ask for me tomorrow, and you shall find me a grave man."

For the novelist a pun is characterization by wit: characters who pun announce themselves, and the figure works by meaning where alliteration and assonance work by sound. Its indecent cousin is the double entendre.