Knock the Fuck Out 

Knock the fuck out, a term used mainly when someone gets punched in the face, thereby resulting in a minor (or major) concussion or simply broken/bloody nose.
Nearly any sort of head-trauma, so long as it's very painful, is considered 'getting' knock the fuck out. You never use 'knock the fuck out' with an 'ed' at the end, because it ruins the point of the gangstuh-speak. Honestly, don't add the 'ed' or you get knock the fuck out.

Me: You better get me my weed by Monday.
John: Or what?
Me: OR YOU GET KNOCK THE FUCK OUT, THAT'S WHAT NIGGA!!
(That Monday)
Me: Bitch you got my shit?
John: No, bitch.
Me: (Punches John in the face.)
Innocent bystander: Oh shit! You just got knock the fuck out!

Knock the Fuck Out by Nyiddle May 28, 2006

knock the fuck out 

Canadian slang;

to knock the fuck out is offering to perform oral sex. Euphemism common among the bath-houses of Toronto and Craig's List. This is unconfirmed.

Imp wants to knock the fuck out of GM.

knock the fuck out by Steve312 January 28, 2008