unbuttons
v. 解开(纽扣)( unbutton的第三人称单数 ); 打开; 表露; 吐露
If you unbutton an item of clothing, you undo the buttons fastening it.
She had begun to unbutton her blouse.
她开始解衬衣扣子。
...his unbuttoned blue coat.
他没有扣上纽扣的蓝色外套