To smack, slap or impede in any way the act of a sexual groping, especially from an annoying boyfriend who just wants to grab a titty or a cheek for grabbin's sake (because that's his ass to grab). This definition is reversible for male-to-female, except most men will opt out of the knock away and allow the grope in almost any instance.
Male: why do you keep blocking me?
Female: I didn't block you, I did the knock away.
by edstar77 June 6, 2016
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