unfasten

verbs

cause to become undone
"unfasten your belt"
unfasten
is derived from
unfastener
is derived from
unfastening
antonym
fasten
is a type of (narrower)
cancel, annul, or reverse an action or its effect
"I wish I could undo my actions"
undo
causes
become undone or untied
"The shoelaces unfastened"
unfasten
become undone or untied
"The shoelaces unfastened"
unfasten
is derived from
unfastening
antonym
fasten
is a type of (narrower)
become open
"The door opened"
open, open up