knock one back

knock back

1. To drink something, usually an alcoholic beverage, quickly. A noun or pronoun can be used between "knock" and "back." Let's get together and knock back some cold ones tonight.
2. To physically force someone or something backwards. A noun or pronoun can be used between "knock" and "back." The rumbling of the earthquake knocked us all back.
3. To cost someone a particular amount of money. A noun or pronoun can be used between "knock" and "back." Geez, how much is this car repair going to knock me back?
See also: back, knock
Farlex Dictionary of Idioms.

knock one back

verb
See knock back a drink
See also: back, knock, one
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions
See also:
  • cut back
  • buck off
  • choke back
  • brush back
  • bring back
  • claw back
  • chop back
  • be/go back to square one
  • come back and see us
  • back to square one
References in periodicals archive
It sounds standard until you knock one back and feel the effects immediately.
You can knock one back in no time, and your palate is ready for number two--or number four, for that matter.
As much as you may want to, it's not the done thing in polite society to hold your nose as you knock one back.
"Don't head straight for the penis - a head massage isn't something he's likely to ask for but most men won't knock one back if it's offered and, once he's had it, he'll be begging for more," she says.