[ uhn-fas-uhn, -fah-suhn ]
See synonyms for: unfastenunfastened on Thesaurus.com

verb (used with object)
  1. to release from or as from fastenings; detach.

  2. to undo or open (something fastened).

verb (used without object)
  1. to become unfastened.

Origin of unfasten

First recorded in 1175–1225, unfasten is from the Middle English word unfastnen.See un-2, fasten

Words Nearby unfasten

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use unfasten in a sentence

  • She laughed and called to Mumps to come and unfasten her veil.

    The Child of Pleasure | Gabriele D'Annunzio
  • He tried first with his own keys to unfasten the flap but the locks defied him.

    The Daffodil Mystery | Edgar Wallace

British Dictionary definitions for unfasten


/ (ʌnˈfɑːsən) /

  1. to undo, untie, or open or become undone, untied, or opened

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012