Definitions:

1. finish a task completely verb
   • We polished of that whiskey faster than I thought we would.
2. finish eating all the food on one's plate or on the table verb
   • They polished off a five pound schnitzel.
3. kill intentionally and with premeditation verb
   • The gangsters polished off the competition.

Synonyms:

• finish
• hit
• mop up