1. knock back - Noun
2. knock back - Verb
cost a certain amount
Source: WordNetknock-back
My love of maple syrup. I've been known to knock back a can over a couple days: A swig here, a swig there, and next thing you know it's gone. It's a habit I have to stave off. I don't want to lose all my teeth. Rufus Wainwright
My daughter's wedding set me back $20,000 Source: Internet
These allow the player to throw lightning bolts and shards of ice, knock back enemies, control hostile technology, and even summon animals like bees and crows to attack targets. Source: Internet
Nick and Nora Charles (played to perfection by William Powell and Myrna Loy) knock back martinis and trade barbs while searching for a missing inventor. Source: Internet
So here you can knock back a bit of Swedish Glögg while tucking into cured salmon and caviar. Source: Internet
Juniors only knock back in a couple of weeks’ time with school holidays looming, so the grandies aren’t out yet, looking all fierce and adorable at the same time! Source: Internet