🄰 vt. sep.
to stiffen sth uporto stiffen up sth
+ muscles, joints使变得僵硬；使变得僵直；使变得不灵活
Driving stiffens up the knees.开车使膝盖变得僵硬。
These clothes restrict freedom of movement and stiffen up the whole body.这些衣服使你行动不便, 让你全身都变得不灵活。
🄱 vi.
(become difficult to move)muscles, joints, person +变得僵硬；变得僵直；变得不灵活
I just stiffened up.我浑身都僵直了。
His knee has stiffened up overnight.他的膝盖在一夜之间变得僵硬起来。
My elbow was starting to stiffen up where I'd landed on it.我用胳膊肘支撑着自己, 结果着力的地方就开始变得僵硬起来。
The battered muscles were starting to stiffen up.遭到重击的肌肉开始变得僵硬起来。