a river in the Moldavian SSR. A right tributary of the Dnestr River. Length, 155 km; basin area 2, 150 sq km. In its upper course the Byk flows through the Kodra Upland, cutting deep canyons into it. In certain years the Byk dries up for periods ranging from a few days to between two and four months, at which times it becomes a chain of lakes. The average annual water discharge at Kishinev is 1 cu m per sec, but at its highest flood stage it reaches 220 cu m per sec. The Bendery-Ungeny railroad line passes through the Byk valley.