defined by the movie Jay and silen Bob strike back when they fight the evil "cock knocker" with bongsabers. Cock knocker has one huge fist which he uses to hit men in the junnks

To cock knock is to it someone in the groin, similar to a fagtag, except you punck or knock on the cock as you would someones front door

To hit someone or something with your penis.

To be slapped in the head with a penis

to be knocked with someones cock

adj-
To be knocked with a cock

To recieve a blow (usually to the head) for wronging another for some reason.

A cock knock is when two men are having sex with a woman, and one goes from the behind, and the other in the front. By the law of physics, the sword player's cocks would "knock" each other.