stiffness

Her initial stiffness began to wear off as we got to know her.

随着我们渐渐了解她，她起初的拘谨也慢慢消失了。

the stiffness of her muscles

她肌肉的结实程度

Everyone was surprised at the stiffness of the sentence/punishment/penalty/sanctions.

每个人都对判决／惩罚／处罚／制裁之重感到吃惊。