off
1.
to make a lot of plants, animals, etc. die :
Some drugs kill off useful bacteria in the user's body.
2.
to stop or get rid of sth :
He has effectively killed off any political opposition.
off
1.
to make a lot of plants, animals, etc. die :
Some drugs kill off useful bacteria in the user's body.
2.
to stop or get rid of sth :
He has effectively killed off any political opposition.
Oxford Advanced Learner's English Dictionary. Оксфордский английский словарь для изучающик язык на продвинутом уровне. 2005