Definitions

1. verb

to remove or undo a fastening, such as a knot, buckle, or lock

“She unfastened the buckle on her jacket.”

2. verb

to loosen or untighten something, such as a screw or a nut

“He unfastened the screw on the old clock.”

3. verb

to disengage or disconnect something, such as a door or a lock

“The door unfastened from its hinges.”

4. noun

the act of removing or undoing a fastening

“The unfastening of the door took several minutes.”