v. t. | 1. | To loose; to unfix; to unbind; to untie. |
Verb | 1. | unfasten - cause to become undone; "unfasten your belt" |
2. | unfasten - become undone or untied; "The shoelaces unfastened" Antonyms: fasten - become fixed or fastened; "This dress fastens in the back" |