stiffen

v. /ˈstɪf.ən/ C1

变僵硬；变硬

To become firm, straight, or unable to bend.

仙境例句

The Frog-Footman sat staring at the sky so long that his legs began to stiffen.

青蛙仆人坐着望天望了太久，两条腿都开始发僵了。