Can mean one of two things:
1) To stroke a penis, either by masturbation or by doing it for someone else
2) To kill someone in Maphia lingo
For definition 1: "I'm whacking off right now.", "Your sister whacked me off last night."
For definition 2: "If I find out Lenny's wearing a wire, you're gonna whack him off.", "I'm going to whack you off if you don't whack off Lenny."
A weirdo who is messed up and also stupid. An absolute speng lord.
My guy you’re a wacky whack nut
stepping things up a notch
taking things to the next level/phase
doing something more briskly than usual
"We 'radded the whack' by going to tescos instead of sainsburys" (implying tescos is better than sainsburys)
being more aggressive suddenly in a game of american football is 'raddin' the whack'
to 'rad the whack' is to do something that little bit more extremely
a catchy name for a 'fist bump'. where your fist hits another person's fist in a victorious manor.
A stupid and/or retarded person(s); Someone who commits general douchiery because it's funny to them when people get mad.
Man, Jimmy is such a Chode Whack. He's constantly making annoying goddamn comments during people's conversations
the electrical charge that instigates ejaculation when masturbating.
Here it comes, I just felt a whack-volt.
To do pretty much nothing while at work. To be lazy and/or accomplish nothing throughout the work day.
Bob is worthless as hell. He is always gin whacking around.