unfasten

American  

[uhn-fas-uhn, -fah-suhn] / ʌnˈfæs ən, -ˈfɑ sən /

verb (used with object)

1. to release from or as from fastenings; detach.

2. to undo or open (something fastened).

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verb (used without object)

1. to become unfastened.

unfasten British  

/ ʌnˈfɑːsən /

verb

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

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Etymology

Origin of unfasten

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

Explanation

When you unfasten something, you loosen or open it. You should wait to unfasten your seatbelt until the car has completely stopped. To fasten is to hook, close, or latch something, and to unfasten it is to undo it. You might unfasten your dog's leash so she can run free on the beach or unfasten the snaps and buttons on your jacket so you can take it off. You can also unfasten your ponytail, letting your hair down, or unfasten the latch on a gate. The Old English root word is fæstnian, "make fast or firm."

Example Sentences

For 12 days, we shared every moment and, surrounded by the kind of beauty only a remote bay in the Pacific could afford, I felt something unfasten in my chest.

From Los Angeles Times • Mar. 8, 2024

To serve the cheesecake, run a knife around the outer edge to loosen it from the pan, then carefully unfasten the sides of the pan and transfer the cheesecake to a cake plate or stand.

From Fox News • Dec. 16, 2021

Operators are supposed to unfasten all of the seat belts after each ride so the next load of people can be buckled in.

From Seattle Times • Sep. 25, 2021

Turn off the heat, allow the pressurized steam to escape, then unfasten the lid and check for doneness; you want your beans to be very tender and quite creamy.

From Washington Post • Jun. 3, 2018

I walk over and begin to unfasten the row of tiny buttons along the back, slipping it over her head once it’s loose enough.

From "Dread Nation" by Justina Ireland