buy除了“买”，还有“获得，赢得”的意思。因此buy time并不是“买时间”，而是“争取时间，拖延时间”。

例句：

Many feel that these latest negotiations are all part of a rebel plot to buy time to try to win more support.

许多人觉得最近的这些谈判是争取时间以赢得更多支持的反叛阴谋的一部分。

He tried to buy time by saying he hadn't been well.

他试图以身体不适为借口来拖延时间。