Meaning: Finish work for the day
Example: We KNOCKED OFF early on Friday to avoid the rush hour queues.
Meaning: Reduce the price of something
Example: They KNOCKED ten pounds OFF when I asked for a discount.
Meaning: Reduce the time required to do something
Example: The new road KNOCKS an hour OFF the journey.
Example: He KNOCKED it OFF and sold it.
Meaning: Produce or create something quickly
Example: I KNOCKED the essay OFF in an hour.