Answer:

unbutton

Answer	Crossword Clue
UNBUTTON	Open, as a shirt
UNBUTTON	Loosen, as a vest
UNBUTTON	Prepare to take off

UNBUTTON	Unfasten, as a coat.
UNBUTTON	Open, as a jacket
UNBUTTON	Open, in a way

Crossword

a puzzle consisting of a grid of squares and blanks into which words crossing vertically and horizontally are written according to clues.