dunk, v. — Green’s Dictionary of Slang

dunk v.

[baseball use dunk, to push (the ball) down through the basket, esp. by jumping so that the hand is above the level of the ring]

1. (US gay) to charge, to use a credit card.

1972

B. Rodgers Queens’ Vernacular 70: dunk to charge something; to use credit cards.

2. (US campus) to humiliate someone.

1999

Eble Campus Sl. Nov. 4: dunk – humiliate: ‘He’s dunkin’ me’.

3. (US black) to outwit, to overcome an opponent by an unorthodox move.

1994

G. Smitherman Black Talk.

4. (Irish) to jump through.

1998

A. Warner Sopranos 85: Chell didn’t dunk out the window but horsed it back and kicked off the break.