Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English

English definition of “unfasten”


verb [I/T]  /ʌnˈfæs·ən/ us  
to make looser or take apart something that fastens or is fastened: [T] Cal loosened his tie and unfastened his collar.
(Definition of unfasten from the Cambridge Academic Content Dictionary © Cambridge University Press)
What is the pronunciation of unfasten?
Browse related topics

You are looking at an entry to do with Unfastening and opening, but you might be interested in these topics from the Opening and closing topic area:

Add Cambridge dictionaries to your browser to your website

Definitions of “unfasten” in other dictionaries

Word of the Day


a type of dark brown beer with a bitter taste

Word of the Day


Read our blog about how the English language behaves.

Learn More

New Words

Find words and meanings that have just started to be used in English, and let us know what you think of them.

Learn More