to destroy sb / sth, especially sb / sth that is badly injured or damaged; to do the last part of sth; to make sth end by doing one last thing
finish sb / sth offinformal
to destroy sb / sth, especially sb / sth that is badly injured or damaged
The hunter moved in to finish the animal off.
finish sth off
to do the last part of sth; to make sth end by doing one last thing
I need about an hour to finish off this report.
Definitions from the Oxford Advanced Learner's Dictionary, 9th edition