ISJUM, a city of the province Ukraine in Russia, the capital of a circle of the same name on the river Jszumez, which near to it falls into the Donez. It is surrounded with walls, but in a neglected condition; and contains four churches, 718 houses, and 4500 inhabitants, whose chief trade consists in the sale of corn and cattle. Lat. 49^{\circ} 12' 30'' N.; Long. 37^{\circ} 30' 5'' E.