a decayed corporate town in Monmouthshire, 14 miles west of Monmouth, at the confluence of the Usk and Gavenny. It was once a walled town, and has the remains of a castle built at the time of the Conquest. The river Usk is here spanned by a noble stone bridge of fifteen arches. It has a town-hall, two banks, gas-works, and a free grammar school, with a fellowship and exhibitions at Jesus College, Oxford. The rich coal and iron mines in the vicinity afford employment to the people, who also engage in the weaving of flannel, &c. Abergavenny appears to have been the Gobannium of Antoninus, and the town of Usk his Burrium. Pop. in 1851, 4797.