unfasten

verb

un·​fas·​ten ˌən-ˈfa-sᵊn 

unfastened; unfastening; unfastens

transitive verb

: to make loose: such as

a

: unpin, unbuckle

b

: undo

unfasten a button

c

: detach

unfasten a boat from its moorings

Synonyms of unfasten

• untie
• loosen
• undo
• unbind

Examples of unfasten in a Sentence

gently unfastened the strings of the baby's hood

Recent Examples on the Web

Transforming the cabin from sitting to sleeping is a group effort that includes unpacking the ladder (usually stowed beneath the seats with the luggage), unfastening the upper bunks, and making the beds. —Emily Manthei, Travel + Leisure, 10 May 2026

After the pink fabric is unfastened from styrofoam beams floating 200 feet out from each island, the sections are towed to shore and rolled up in bundles, Morgan said. —Miami Herald Archives, Miami Herald, 29 Apr. 2026

If your button-down outfit is in need of a little spice, a quick trick is to unfasten the top and slip out a single shoulder. —Sri Rain Stewart, InStyle, 13 Jan. 2026

Skinny Pedro unfastened his seat belt and turned his seat around to face me. —Literary Hub, 12 Jan. 2026

Word History

First Known Use

14th century, in the meaning defined above

Rhymes for unfasten

• capsaicin
• disseisin
• freemason
• stonemason
• subbasin
• washbasin
• basin
• caisson
• chasten
• hasten
• jason

Kids Definition

unfasten

verb

un·​fas·​ten ˌən-ˈfas-ᵊn 

: to make loose: as

a

: unpin, unbuckle

b

: undo sense 1

unfasten a button

c

: detach

unfasten the boat from its moorings