Former name (1642--1855): Van Diemen's Land an island in the S Pacific, south of mainland Australia: forms, with offshore islands, the smallest state of Australia; discovered by the Dutch explorer Tasman in 1642; used as a penal colony by the British (1803--53); mostly forested and mountainous. Capital: Hobart. Pop: 479 958 (2003 est). Area: 68 332 sq km (26 383 sq miles)