Untie

Verb

 * 1)  To loosen, as something interlaced or knotted; to disengage the parts of; as, to untie a knot.
 * 2)  To free from fastening or from restraint; to let loose; to unbind.
 * 3) To resolve; to unfold; to clear.
 * 4)  To become untied or loosed.

Antonyms

 * tie

Thesaurus
cast off, detach, disembarrass, disembroil, disencumber, disengage, disentangle, doff, free, liberate, loose, loosen, release, remove, take off, unbar, unbind, unbolt, unbridle, unbuckle, unbutton, uncage, unchain, unclasp, undo, unfasten, unfetter, ungag, unglue, unhandcuff, unhobble, unlace, unlash, unlatch, unleash, unlock, unloose, unloosen, unmanacle, unmuzzle, unpen, unpinion, unscramble, unshackle, unstick, unstrap, untangle, untether, untruss, untwine, unyoke, weigh anchor