buy off
To pay someone to coerce them into doing something. A noun or pronoun can be used between "buy" and "off." Don't worry, the doorman won't say anything—I bought him off. Her campaign for mayor will be ruined if the public learns how many people she's bought off over the years.
buy someone off
to bribe someone to ignore what one is doing wrong. Do you think you can buy her off? The mobster tried to buy off the jury.
buy off
Pay to get rid of a claim or opposition, or to avoid prosecution, as in He was caught trying to buy off the opposing candidate. [First half of 1600s]
buy off
v. To bribe someone in order to ensure cooperation: I didn't get a speeding ticket because I bought off the police officer. The mobster avoided jail by buying the judge off.