unbutton JUST WRITTEN FOR YOU
/ʌnˈbʌtən/ · un·but·ton
verb
- To open (something) by undoing its buttons. She unbuttoned her coat as soon as she stepped into the warm room.
- To become open because its buttons have been undone. The shirt unbuttoned itself when the child tugged at the collar.
Did you know? The verb ‘unbutton’ first appeared in print in the 1820s, and by the late 19th century it was being used figuratively to describe a relaxed, informal demeanor.