英和和英

to undo a button―（上衣のボタンなら）―unbutton one's coat

to undo a button―unbutton one's coat

to fasten a coat with buttons―button up a coat

A button comes undone―（靴のボタンなら）―A shoe comes unbuttoned.

undo the buttons of

A button has come off

A button is off.

A button comes undone

A shoe comes unbuttoned.

not buttoned

A button fell off.

a button on a coat

fasten buttons

provide with buttons

to fasten one's coat with buttons―button one's coat

to sew on a button

to sew a button on

A button is off.

to finger a button―fumble a button

fasten with buttons

I can't button up my coat.

A button comes off.

to press a button

push the button down

A button has come off.

to press the button

not worth a button

press a button

at the pressing of a button

Click the button