to buy sb off or to buy off sb
+ voters, union, child, witness向…行贿；拉拢；收买
policies designed to buy off the working-class vote旨在拉拢工薪阶层选民的政策
In buying your children all these things, you are in a sense buying them off.你给孩子买这些东西的时候, 从某种意义上你是在收买他们。
They tried to buy off the witnesses.他们试图收买目击证人。