IPA: //ʌnˈstræp//
KK: /ʌnstræp/
To take off or loosen a strap that is holding something in place.
She had to unstrap the backpack before she could take it off her shoulders.
Past: unstrapped
Past Participle: unstrapped
Unstrap → It is formed from "un-" (meaning not or to reverse) and "strap" (from Old English "strap", meaning a strip of leather or material used for fastening). The word "unstrap" means to remove or loosen a strap, effectively reversing the action of fastening something with a strap.
Think of 'un-' meaning to reverse and 'strap' as a fastening material — so unstrap means to reverse the fastening action.