verb ·Uncommon ·Advanced level

Definitions

Verb

1. 1
   To detach from any connecting agency or link; to disconnect. transitive

   "He doth unfasten so and shake a friend."

2. 2
   become undone or untied wordnet
3. 3
   To come unloosed or untied. intransitive
4. 4
   cause to become undone wordnet

Synonyms

All synonyms

undountiecast offdetachdisconnectdisengage

Antonyms

All antonyms

attachbuttonbutton updo up

Example

More examples

"Tom tried to unfasten his seatbelt."

Etymology

From un- + fasten.

Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.