Do not get this confused with yet. It doesn't mean yet. It could mean you threw something and one would say, you 'yeeted' that thing. It could also be said in place of yes.
Example one:
Person 1: You ready?
Person 2: YEET
Example two:
Person 1: Throw the ball!
Person 2: *throws ball* YEET
When you're down with something.
Person one: Hey wanna go to the mall?
Person two: Aight I'm hip.