To give a girl a damned good seeing to. Preferably after licking her snatch and most definitely in at least 2 or 3 positions. The conditions of 'giving a good moyseying' also require that you must have a girlfriend (or
wife) whilst giving the moyseying (to someone else) and that after you're through moyseying, you must describe in detail to the girlfriend (or
wife) exactly what a good moyseying you gave to the girl. This can be done in person, or, if you're feeling especially brave or
stupid, all over an internet messageboard. Bonus points if you, the
wife, the moysey'd girl and 30 or so of your friends also
use this message board.