unloose (v.)youdaoicibaDictYouDict[unloose 词源字典]
mid-14c., "relax;" late 14c., "to set free," from un- (2), used here emphatically, + loose. Old English had unliesan "unloose, set free." Related: Unloosed; unloosing.[unloose etymology, unloose origin, 英语词源]