NIDUM or NIDUS, a town of Britain, situated according to the Itinerary (p. 484), on the road from Isca Dumnuniorum to Isca Silurum, and consequently in the territory of the Belgae. This site, however, is in all probability false; and it appears rather to have been a town of the Silures, the modern Neath, on the river of that name in Glamorganshire. (Camden, p. 735.) [T.H.D]