BP
noun
1
in blackjack counting teams, the player who places the large bets based on cues from other members of the team who have been counting cards at a particular table. An intialism for 'big player' US, 1991.
2
in American casinos, a serious gambler. The initials stand for 'big player' US, 1985.
3
a young prostitute. An abbreviation of 'baby pro' US, 1971