HAY, a town of Brecknockshire, in Wales, seated near the confluence of the rivers Wye and Dulas. It was a town of good note in the time of the Romans; it being then fortified with a castle and a wall, which were ruined in the rebellion of Owen Glendower. It is at present a pretty good town; and the market is large for corn, cattle, and provisions. W. Long. o. 56. N. Lat. 52. 10.