unfasten

Unfasten is a verb meaning to release or loosen something that is fastened, or to open or detach a fastening. It is typically used as a transitive verb, with an object such as a buckle, button, zipper, latch, or strap.

Etymology and form: The word is formed by adding the prefix un- to fasten. Fasten itself comes from older Germanic roots meaning to make firm or secure; the prefix un- reverses that sense, yielding the action of releasing or undoing a fastening.

Common usage: Unfasten is used for a range of physical contexts, including clothing (buttons, zippers, belts), hardware (bolts, clasps, locks), and structural fixtures (latches, doors, gates). It also describes releasing restraints or bindings, such as unfastening a seat belt or a harness. In literary or formal writing, unfasten can be part of a metaphorical sense, referring to the loosening of bonds or constraints in a more abstract way.

Nuance and synonyms: Unfasten emphasizes the act of removing a fastening that secures one part to another. Related terms include undo, unbutton, unzip, unclip, and disengage, each with slightly different typical contexts. In everyday speech, more general verbs like open or undo are often used, while unfasten remains common in technical, legal, or historical writing.

See also: Unfastened, the adjectival form describing something that has had its fastenings released.