(loosely) The United Kingdom.

The island of Great Britain, consisting of England, Scotland and Wales, especially during antiquity.

England, Scotland and Wales in combination.

(obsolete) Brittany.

(in the plural) The British Isles.

(historical) The British state and its dominions and holdings; the British Empire.

(in the plural) The British Empire.

(now rare, historical) An ancient Briton.

(obsolete) Briton; British.