verb (used with object)
to loose or unfasten (anything tied); let or set
loose by undoing a knot.
to undo the string or cords of.
to undo, as a cord or a knot; unknot.
to free from restraint.
to resolve, as perplexities.
verb (used without object)
Origin: before 1000; Middle English untyen, Old English untīegan.
Can be confused: unite