1: Verb; The female equivalent of "Jerkin' Off" where the woman takes a set number of fingers and proceeds to rub at her vagina profusely for sexual pleasure.
2: Verb; When a man or woman begins to itch his/her junk, and it feels so good that they either jizz themselves almost immediately, or they continue to masturbate following the relief of the itch.
Ex. 1: I just walked in on my sister scratchin' off like a lotto ticket.
Ex. 2: I jizzed myself when I finally scratched off to this itch I had for an hour.