Green’s Dictionary of Slang

pound n.5

1. an act of sexual intercourse [pound v.2 (1)].

[US]Source Nov. 137: Girls wants hugs, dudes want a pound and, if lucky, a light-up.

2. (US black) the hitting together of fists or a slap on the back used as a greeting [SE pound, to hit].

[US]R. Price Clockers 436: Three grinning teenagers [...] walked into the store, hands raised for a pound.
[US]Source Nov. 182: The waiter gives Jay a pound. ‘Haven’t seen you for a long while, man.’.
[US]‘Grandmaster Flash’ Adventures 239: As [Biggie Smalls] got up to leave, he gave me a pound[to] let me know that he appreciated my work.
[US]‘Dutch’ ? (Pronounced Que) [ebook] ‘Shit, we already set it,’ YaYa chuckled, giving Montez a pound.