A paraprosdokian/pærəprɒsˈdoʊkiən/ is a figure of speech in which the latter part of a sentence or phrase is surprising or unexpected in a way that causes the reader or listener to reframe or reinterpret the first part. It is frequently used for humorous or dramatic effect, sometimes producing an anticlimax. For this reason, it is extremely popular among comedians and satirists. Some paraprosdokians not only change the meaning of an early phrase, but they also play on the double meaning of a particular word, creating a form of syllepsis.
"Paraprosdokian" comes from Greek "παρά", meaning "against" and "προσδοκία", meaning "expectation". Canadian linguist and etymology author William Gordon Casselman argues that, while the word is now in wide circulation, "paraprosdokian" (or "paraprosdokia") is not a term of classical (or medieval) Greek or Latin rhetoric, but a late 20th-century neologism. The fact that the word does not yet appear in the Oxford English Dictionary is evidence of its late coinage. The term "prosdokia" ("expectation") occurs with the preposition "para" in Greek rhetorical writers of the 1st century BCE and the 1st and 2nd centuries CE, with the meaning "contrary to expectation" or "unexpectedly." These four sources are cited under "prosdokia" in Liddell-Scott-Jones, Greek Lexicon.