When a seriously inebriated male (usually almost to the point of alcohol poisoning) vomits all over the head of a girl performing oral sex on him. Also known as a "peurto rican bath."
I gave that slut a dirty nacho and she didn't even notice.
by Chuck the Jay November 02, 2006
A game where several guys circle jerk onto a nacho. Last one to spooge has to eat it.
Damn! I lost at dirty nacho again!
by manrower April 21, 2009