The word ' unfasten ' has 3 syllables : un-fas-ten
THREE
"Quickly unfasten my seatbelt, I can't move!"
I could not unfasten my seat belt and had to ask for help from someone at the gas station. It is very difficult to unfasten a bracelet with one arm in a cast.
Fasten.
Fasten..
Since the building changed ownership, we had to unfasten the sign, and install a new one.
To free or unfasten.
It means undo.
undo
Herman quickly worked to unfasten his apron from working in the smithy, so he could change for dinner.
unzip
unfasten discourage