- Machinery. a pistonlike reciprocating part moving within the cylinder of a pump or hydraulic device.
- Automotive. a pistonlike part in the valve of a pneumatic tire.
- Also called force cup, plumber's friend, plumber's helper. a device consisting of a handle with a rubber suction cup at one end, used as a force pump to free clogged drains and toilet traps.
- a person or thing that plunges.
- a reckless bettor or speculator.
Origin of plunger
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for plunger
Stick it in his arm, push the plunger, pull it out; and wait for him to die.Life Sentence
He'll remember the fellow they called 'the plunger,' and 'the dead-game sport.'Rival Pitchers of Oakdale
The plunger is loaded with a spiral spring, and has a ball valve, as shown.Gas and Oil Engines, Simply Explained
Walter C. Runciman
In this form of grenade a safety pin holds the plunger from the cap.Manual of Military Training
James A. Moss
"And the little soft has nibbled at Plunger's bait," laughed Stanley.The Hero of Garside School
J. Harwood Panting
- a rubber suction cup fixed to the end of a rod, used to clear blocked drains
- a device or part of a machine that has a plunging or thrusting motion; piston
- informal a reckless gambler
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Word Origin and History for plunger
1610s, "one who plunges," agent noun from plunge (v.). As a mechanism, 1777.
Online Etymology Dictionary, © 2010 Douglas Harper