English slang expression which can be used as a noun or a verb:
1 Knock off (noun), an item intended to look like something it is not, such as an expensive watch or designer clothes.
Knock off (verb) can have a number of meanings depending on context:
2 to stop working for a short break;
3 to leave work at the end of the day;
4 to steal or remove;
5 to kill or severely chastise someone;
6 to try to get close to someone for romance or casual sex;
1 That piece of shit isn’t a Rolex, it’s a knock off;
2 Let’s knock off for a cuppa, I’m parched;
3 It’s gone five o’clock, let’s knock off;
4 I’m going to knock off a few pens from the office;
5 They’re going to knock off that fat bastard he’s really pissed them off.
6 I’m going to knock off that bird from HR;
by AKACroatalin April 19, 2015
To knock someone off their higher position....
Man...this hustlin' shit is harder than I thought and that bitch -niggas doin' good inna muthafuka and I'm struggling.
Fuk that shit bro I'ma "knock off' that nigga man reelniggashit....
by Tione June 2, 2009
An item that looks exactly like an original product but lacks the expensive designer label and is replaced with a fake one. Usually costs half the price with half the style appeal.
I hate those Coach knock off purses with the little "G's" on them instead of little "C's"
by ~*erin*~ April 10, 2004
Australian, to end the days work, to clock out.
2) colloq to steal
I knocked off work mate and seen some bastrad knocked off me car stereo.
by herbie August 31, 2004
The act of masturbating whilst really high so that when you jizz all the blood rushes from your head and you pass out. May be hard to achieve.

Also known as Jacking Black.
X: "Ben and I tried Knocking Off last night"
Y: "No Way! You guys are crazy! Any success?"
X: "Yep, I totally Knocked Off!! Ben didn't manage to though. It really isn't easy!"
by Jacking it in San Diego April 18, 2015
v. to behave like a moron after consuming intoxicating substances.
Ok, I'll let you drink this everclear, but promise not to knock off.
by dinki August 25, 2003