CLYTHA, a chapelry in that part of the parish of LLANARTH which is in the lower division of the hundred of RAGLAND, county of MONMOUTH, 5 miles (N. by W.) from Usk, containing 376 inhabitants. On the summit of an eminence at the extremity of the Clytha hills is a small encampment, which retains marks of having been strongly fortified.