'cap' used to mean 'game' on the west coast.'You aint got no cap' was like telling a dude he didn't have game. you COULD stretch that definition to 'exaggeration' (the root of old school toxic game) no cap = I'm not exaggerating/tryna run came on youj.dang i'm tired.
IG: amadu_me"...Whateva, man..." (c) Redman