bombardier beetle definition by Webster's New World
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio. Used by arrangement with John Wiley & Sons, Inc.
any of various ground beetles (esp. genus Brachinus) that protect themselves by discharging an irritating fluid that vaporizes with a popping sound on contact with the air
bombardier beetle definition by American Heritage Dictionary
Any of various beetles of the genus Brachinus and related genera that expel an acrid, volatile secretion from the abdomen when disturbed, making an audible sound.