- principal island of the United Kingdom, including England, Scotland, & Wales, & administratively including adjacent islands except the Isle of Man & the Channel Islands
- popularly the United Kingdom of Great Britain and Northern Ireland
Of the island of Great Britain, to disambiguate from Britain 'Brittany'. In Middle English (late 13th century) as Bretaygne the Grete, imitating Anglo-Norman la Grande Brettayne and 12th-century Latin maior Britannia. King James VI and I in 1604 proclaimed himself "King of Great Britain, France and Ireland".