un·tie 
(ŭn-tī)
(ŭn-tī)v. un·tied, un·ty·ing (ŭn-tīĭng), un·ties
v.tr.
1. To undo or loosen (a knot or something knotted).
2. To free from something that binds or restrains: untie a horse from a tree.
3. To straighten out (difficulties, for example); resolve.
v.intr.
To become untied.