To jerk off. Comes from the sound that is produced while a man is masturbating.
She didn't put out again, it's our third date. I think I'll just fap off.
by bitofafry November 04, 2013
1 more definition
two begin to fap. one finishes. one continues.
there are two people who disagree about who can out fap the other and so they have a fap off
by The American American November 04, 2013