Source : Webster's Revised Unabridged Dictionary (1913)

Untangle \Un*tan"gle\, v. t. [1st pref. un- + tangle.]
   To loose from tangles or intricacy; to disentangle; to
   resolve; as, to untangle thread.

         Untangle but this cruel chain.           --Prior.

Source : WordNet®

untangle
     v 1: release from entanglement of difficulty; "I cannot extricate
          myself from this task" [syn: {extricate}, {disentangle},
           {disencumber}]
     2: become or cause to become undone by separating the fibers or
        threads of; "the sweater unravelled" [syn: {unravel}, {unknot},
         {unscramble}, {unpick}] [ant: {ravel}, {ravel}]