whoopee cushion[hwo̵op′ē, wo̵op′ē]
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio.
a device for playing practical jokes, consisting of an air-filled pillow with a valve that emits a sound like that of gas being expelled from the bowels when someone sits upon it
also sp. whoopie cushion
Used by arrangement with John Wiley & Sons, Inc.