buckle

I felt faint and my knees began to buckle.

我感到眩晕，腿也站不直了。

But these were difficult times and a lesser man would have buckled under the strain.

但当时是困难时期，脆弱的人肯定会被压力压垮。

He fastened his belt with a shiny buckle.

他用一个闪亮的搭扣系紧了他的皮带。