If you untangle a confused or complicated situation, you make the different things involved clear, or put the situation right. Lawyers and accountants began trying to untangle the complex affairs of the bank = disentangle
If you untangle something that is knotted or has become twisted around something, you undo the knots in it or free it. He was found desperately trying to untangle several reels of film. a light, non-sticky mousse which untangles hair and adds brilliant shine