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1.
The act of whacking (hitting, slapping, kicking, punching, pinching, etc. would go under the category of whacking) the testicles, used to express joy or disgust toward a male - often performed with a cleat
Girl 1 - Oh my gosh! Rick is so annoying. He keeps playing hard to get with me.

Girl 2 - Why don't you give him a good nadwhack? That'll punish him for being so annoying, yet he'll be completely charmed by your abrasive show of affection/anger. Here, take one of my cleats.
by ObeyTheWillow January 21, 2012