Sexual slang (U.K, East Midlands, South Yorkshire, Lancashire (localised) :When men brag to their mates about sex with a very attractive women.
EG:
"I can't believe I knacked her"?
Anecdotally lying or exaggerating popping a girls cherry.
E.G:
"I knacked her ya know?"
Or similarly gloating about "breaking in" or "destroying" a supposed virgin (slang for wild, kinky, hard or just passionate sex) a woman known to be classy, and/or hard-to-get (usually to other lads). Or anal sex with a women :
"I PROPER knacked her!"
Conventionally among friends being deliberately as innapropriate, forthcoming or sexist, common as possible by replacing: "Knacked her."
1) A person who is exhibiting one or more of the following symptoms or habits: sleep deprivation, indifference to the world, lack of motor skills, no motivation to exist on earth any longer, poor decision making, and the occasional urge to kill yourself. Becoming knacked out is usually a result of intense mental or physical duress over long periods of time.
When a person is so annoying that they get you really mad and the only way to stop them doing what they are doing is to give them a single powerful punch to the face which knocks them unconscious, they are now said to be "knocked the fuck out". This is only achieved if it is a single punch which knocks them unconscious.