（做某事或付款以）封住…的嘴
to pay someone or do something for someone, so that that person does not tell anyone something that they know about and that you want to remain secret
What will we have to do to buy her silence? 为了封住她的嘴我们该怎么办？
He was effectively trying to buy my silence.
It was generally thought that the job offer was part of an attempt to placate her and buy her silence.
She was accused of making a payment of $2.1 million to buy the silence of a witness.
So was this sum of money given in compensation or was it an attempt to buy his silence?
See also: buy verb (PAY FOR)