From Proto-Germanic*taglą, from Proto-Indo-European*dek-. Cognate with Middle Low German tagel(“twisted whip”), Old High German zagal(“animal’s tail”) (dialectal German Zagel), Old Norse tagl(“horse’s or cow’s tail”), Gothic 𐍄𐌰𐌲𐌻(tagl, “hair of the head”); and, beyond Germanic, with Old Irish dūal(“lock of hair”).