1. Not buttoned
   "the wind picked up the hem of her unbuttoned coat";
   - unfastened
    
2. Not under constraint in action or expression
   "this unbuttoned and disrespectful age";
   - unlaced

1. Undo the buttons of
   "unbutton the shirt"

See also: open-collared, unrestrained

Type of: undo

Antonym: button, buttoned