·noun The firing pin of a breechloader.
II. Plunger ·noun One who, or that which, plunges; a diver.
III. Plunger ·noun A boiler in which clay is beaten by a wheel to a creamy consistence.
IV. Plunger ·noun One who bets heavily and recklessly on a race; a reckless speculator.
V. Plunger ·noun A long solid cylinder, used, instead of a piston or bucket, as a forcer in pumps.