- an island of the Russian Federation in the Sea of Okhotsk, N of Japan: formerly (1905-45) divided between the Soviet Union and Japan. 29,100 sq. mi. (75,369 sq. km).
- an island in the Sea of Okhotsk, off the SE coast of Russia north of Japan: fishing, forestry, and mineral resources (coal and petroleum). Capital: Yuzhno-Sakhalinsk. Pop: 546 500 (2002). Area: 76 000 sq km (29 300 sq miles)Japanese name (1905–24): Karafuto