Meaning of PLUNGER in English
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.
Concise Oxford English vocab. Сжатый оксфордский словарь английского языка. 2004