Source : Webster's Revised Unabridged Dictionary (1913)

Unloose \Un*loose"\, v. t. [1st pref. un- (intensive) + loose.]
   To make loose; to loosen; to set free. --Shak.

Unloose \Un*loose"\, v. i.
   To become unfastened; to lose all connection or union.

Source : WordNet®

unloose
     v 1: grant freedom to; free from confinement [syn: {free}, {liberate},
           {release}, {unloosen}, {loose}] [ant: {confine}]
     2: loosen the ties of; "unloose your sneakers" [syn: {unloosen}]