a group of islands in W Europe: Great Britain, Ireland, the Isle of Man, and adjacent small islands. 120,592 sq. mi. (312,300 sq. km).
British Dictionary definitions for British Isles
British Isles
plural noun
1.
a group of islands in W Europe, consisting of Great Britain, Ireland, the Isle of Man, Orkney, Shetland, the Channel Islands belonging to Great Britain, and the islands adjacent to these
British Isles in Culture
British Isles definition
The islands of Great Britain and Ireland and a number of smaller islands off their coasts.