knock off

In the verb sense of stopping work, said to be from the practice aboard slave galleys to have a man beat time for the rowers by knocking on a block or drum; when he stopped, the rowers could rest.

knock off (plural knock offs)

1. Alternative form of knockoff
2. A device in a knitting machine to remove loops from the needles.

knock off (third-person singular simple present knocks off, present participle knocking off, simple past and past participle knocked off)

1. (intransitive, slang) To halt one's work or other activity.

   I think I'll knock off for the evening and go to bed.

2. (transitive, slang) To kill.

   The mobsters hired the guy to knock off their enemies.

3. (transitive) To remove, as a discount or estimate.

   They agreed to knock off 20% of the price.

4. (transitive, slang) To rob.

   They decided to knock off a liquor store downtown.

5. (transitive) To make a copy of, as of a design.

   They send people to the shows in Milan for "ideas", which means knocking off the designs they guess would sell.

6. (transitive) To assign (an item) to a bidder at an auction, indicated by knocking on the counter.
7. (transitive, slang) To have sex with.
   • 1965, Claude Brown, ‎Manchild in the Promised Land

     I took her down to Basin Street and to a movie, then took her to my room and knocked her off.

8. (transitive, informal) To accomplish hastily.

   I knocked off a couple of quick sketches before the design meeting.