A tool to clear out a clogged toilet. Consists of a handle upon which is mounted a chamber of sorts which is pressed into the toilet's drain to force the blockage out.

Toilet plungers come in three varieties: the wimpy hemispheric ones which have no capacity and do not develop enough pressure, the ordinary ones which are okay, and the big-ass blue ones sold under the name "Master Plunger" which kill clogs dead.

Also known as a plumber's helper.