1. pump and dump - Noun
2. pump and dump - Verb
(finance) A form of financial fraud where the fraudster buys stocks cheaply, generates excitement about those stocks to create a temporary price increase, then sells the stocks before the price goes back down.
Synonym: buy, lie and sell high
(slang) A situation where a woman uses a breast pump and then discards the milk, typically because she has had an infection, or has been drinking alcohol.
(slang) A situation where a person has sex with a partner on a single occasion, without immediate intention of further contact or pursuing a serious relationship.
Synonyms: fuck and chuck, hit it and quit it, smash and dash, one-night stand
(slang) To use a breast pump and then discard the milk, typically because one has had an infection, or has been drinking alcohol.
(transitive, slang) To have sex with a partner on a single occasion, without intention or prospects of further contact, or engaging in a serious relationship.
Source: en.wiktionary.orgpump-and-dump