to masturbate
jack off
normally used for a guy
but girls can also use it

When you don't have any actual porn and you fap with nothing but your imagination.

masturbating vigorously, usually to Spankwire
and between WoW raids

To have a wank (masturbation)

Fappin': Equivalent to words such as "smashing", "amazing" and the like.

Also means to yank ones penis ever so sensually.

When someone is stuck inside for too long with nothing to do they may go crazy with fappin' fever (uncontrollable masturbation).

The disgraceful act of submitting to ones own rubmission, either by the wearing out of ones arm muscle, or ejaculation.
You tap out on the bed, wall, counter, table, couch, or what ever you are closest to.