un·​fas·​ten | \ˌən-ˈfa-sᵊn \
unfastened; unfastening; unfastens

Definition of unfasten 

transitive verb

: to make loose: such as

a : unpin, unbuckle

b : undo unfasten a button

c : detach unfasten a boat from its moorings

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Synonyms & Antonyms for unfasten


unbind, undo, unlash, untie


bind, fasten, knot, lash, tie

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Examples of unfasten in a Sentence

gently unfastened the strings of the baby's hood

Recent Examples on the Web

For their Spring 2018 show, Eckhaus Latta cast artist Maia Ruth Lee, who strutted out in a snap-front cardigan dress unfastened at the center to reveal her pregnant belly. Maria Ward, Vogue, "Kirsten Dunst Confirms Her Pregnancy in the New Rodarte Lookbook," 30 Jan. 2018 At the ATM, Dinsmore unfastened her seatbelt, and took out $300 in cash. Chris Harris, PEOPLE.com, "S.C. College Student Recounts Harrowing Escape from Alleged Kidnappers: ‘I’m Going to Get Myself Out of This’," 4 Aug. 2017 But Tuesday’s show painted a different musical picture — one of a woman who long ago unfastened herself from the limitations of labels foisted upon her: Alternative. Michael James Rocha, sandiegouniontribune.com, "In concert, a richer Natalie Merchant emerges," 19 July 2017 Unfasten them from the back seat, pull them into the front and push them out your window, oldest ones first. Malia Wollan, New York Times, "How to Escape From a Car in Water," 14 Apr. 2017 Leah ran down the bleachers and unfastened the clips on Grimes’s shoulder pads. Adam Davidson, The New Yorker, "Can Technology Make Football Safer?," 9 Jan. 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'unfasten.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of unfasten

14th century, in the meaning defined above

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Time Traveler for unfasten

The first known use of unfasten was in the 14th century

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More Definitions for unfasten



English Language Learners Definition of unfasten

: to make (something) loose


un·​fas·​ten | \ˌən-ˈfa-sᵊn \
unfastened; unfastening

Kids Definition of unfasten

: to make or become loose He unfastened the buckle.

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Comments on unfasten

What made you want to look up unfasten? Please tell us where you read or heard it (including the quote, if possible).


something that serves to warn or remind

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