[Ir. calad, hard].
Also In Caladbolg. The lightning sword belonging to several early Irish heroes, notably Fergus mac Róich. With it Fergus chops off the tops of three hills in Meath. Fergus mac Léti has a sword much like it called Caladhcholg. Several commentators have seen it as an anticipation of the Arthurian Excalibur. See also CALEDFWLCH.