• (British) IPA: /ˈbɹɪt.ən/, [ˈbɹɪt.n̩]
• (America) IPA: /ˈbɹɪt.ən/, [ˈbɹɪɾ.ᵊn̩], [ˈbɹɪʔ.ᵊn̩]

From Middle English Britayne, Breteyn, from Anglo-Norman Bretaigne, Bretaine, from Latin Brittannia, variant of Latin Britannia, from Britannī; reinforced by native Old English Breten, from the same Latin source.

1. (loosely) The United Kingdom.
2. The island of Great Britain, consisting of England, Scotland and Wales, especially during antiquity. [from 10th c.]
3. England, Scotland and Wales in combination.
4. (obsolete) Brittany. [from 13th c.]
5. (in the plural) The British Isles.
6. (historical) The British state and its dominions and holdings; the British Empire. [from 17th c.]
7. (in the plural) The British Empire. [from 19th c.]

• (island) Gramarye

• Breton
• British
• Briton, Britton
• Britannia

• Brittany
• Battle of Britain
• Broken Britain
• proto-Britain

• French: Grande-Bretagne (only full name is used for the island)
• German: Britannien
• Italian: Gran Bretagna (only full name is used for the island)
• Portuguese: Bretanha
• Russian: Брита́ния
• Spanish: Gran Bretaña (only full name is used for the island)

From (adjective and noun, plural Britannī), apparently from Brythonic languages (compare owl Priten).

Britain (plural Britains)

1. (now, rare, historical) An ancient Briton. [from 15th c.]
   • 2002, L. C. Lambdin, R. T. Lambdin, Companion to Old and Middle English Literature, page 12:

     The Britains’ struggles with the Scots and Picts [...] led to the Britains asking the Romans for help in constructing a great wall.

Britain

1. (obsolete) Briton; British. [16th]
   • 1596, Edmund Spenser, “Book IV, Canto XI”, in The Faerie Queene. […], London: […] [John Wolfe] for William Ponsonbie, →OCLC ↗:

     mightie Albion, father of the bold / And warlike people which the Britaine Islands hold […].