Against the chance that you have been posting on AWADtalk for almost 2 1/2 years and you are, notwithstanding that, unfamiliar with the meaning your chosen signature has in common parlance on this side of the Atlantic, if not on your own side of the Atlantic, I refer you to a page of definitions in A-H, a source you have considered authoritative yourself in the past:

http://dictionary.reference.com/search?q=twat