The act of getting a gay man off. Possible with your hand or mouth. Or both. The word is a combination of 'Manos' and 'Jerk Off'.
"Hey mate, how was last night in Club X?"
"It was good, I got a manoff."
"Ah sweet, good work"
A contest of virility between two men, as demonstrated in Cyborg (1989), in which both men tear off their shirts and exchange screams of rage until one can no longer handle the other’s machismo.
Watch the man-off scene in Cyborg.
To masturbate, or to otherwise do something private and/or embarrassing.
Anthony: Steve, your a douche, why don't you just go man off in the corner.
After seeing a very attractive naked woman on the beach, Steve felt the sudden urge to man off.