n.
Pronunciation: ' pl ə n-j ə r
Function: noun
Date: 1611
: one that plunges: as a : DIVER b : a reckless gambler or speculator c (1) : a sliding reciprocating piece driven by or against fluid pressure especially : PISTON (2) : a piece with a motion like that of a ram or piston d : a rubber suction cup on a handle used to free plumbing traps and waste outlets of obstructions