- a group of over 70 islands off the N coast of Scotland, separated from the mainland by the Pentland Firth: constitutes an island authority of Scotland; low-lying and treeless; many important prehistoric remains. Administrative centre: Kirkwall. Pop: 19 310 (2003 est). Area: 974 sq km (376 sq miles)Related word: Orcadian
name of a group of islands off the north coast of Scotland, from Old Norse Orkney-jar “Seal Islands,” from orkn “seal,” probably imitative of its bark. Related: Orkneyman.