UNDO v.
To loose; to open; to take to piece; to unfasten; to untie; hence, to unravel; to solve; as, to undo a knot; to undo a puzzling question; to undo a riddle. Tennyson. Pray you, undo this button. Shak. She took the spindle, and undoing the thread gradually, measured it. Sir W. Scott.