Plunger

plunger

1. a rubber suction cup fixed to the end of a rod, used to clear blocked drains

2. a device or part of a machine that has a plunging or thrusting motion; piston

---

plunger [′plən·jər]

(design engineering)

A wooden shaft with a large rubber suction cup at the end, used to clear plumbing traps and waste outlets.

(electromagnetism)

piston

(engineering)

force plug

(mechanical engineering)

The long rod or piston of a reciprocating pump.

---

plumber’s friend, force cup, plumber’s helper, plunger

A tool consisting of a rubber suction cup attached to a handle; set over a plumbing trap (or the like) and worked with a pumping action to clear the trap of minor obstructions.

---

Plunger 

(also ram), a piston that has a smooth generatrix (generating surface) or annular grooves and is substantially longer than it is wide. Plungers are chiefly used in hydraulic machines, where they serve as components of pumps, of hydraulic presses and lifts, of slide valves in hydraulic drives, and of multistage gas compressors.