When someone knocks so hard that you think it's the cops.
You scared the crap out of me! Why'd you have to cop knock? I was smoking weed man and I thought it was the cops and I totally freaked out.
by Turbo Werewolf March 15, 2005
1 more definition
A loud, startling, authoritative knock usually used by law enforcement to announce their presence.
Hey easy with the cop knock Fred, my kid is trying to sleep.
by Soice Feos November 07, 2010