plunger
Concise Oxford English Dictionary © 2008 Oxford University Press:
plunger/ˈplʌnʤə(r)/
▶noun
- 1 a part of a device or mechanism that works with a plunging or thrusting movement.
■ a device consisting of a rubber cup on a long handle, used to clear blocked pipes by means of suction.
- 2 informal a person who gambles or spends money recklessly.
'plunger' also found in these Oxford entries:

