unfasten
/ˌʌnˈfɑːsən/verb
with obj.
1- open the fastening of; undo (something)解开; 松开; 打开：
Allie stands before the mirror unfastening her earrings
艾莉站在镜子前解下耳环
as adj. unfastened he had left the door unfastened.他没锁上门。
1.1
- no obj. become loose or undone解开; 打开。