UNBUTTON
Meaning of UNBUTTON in English
/ ˌʌnˈbʌtn; NAmE / verb
[ vn ] to undo the buttons on a piece of clothing :
He unbuttoned his shirt.
OPP button (up)
Oxford Advanced Learner's English Dictionary.
Оксфордский английский словарь для изучающик язык на продвинутом уровне.
2005