a member of Celtic tribes which inhabited Britain before, during, and after the Roman occupation

A Briton is often referred to in broad terms as being an inhabitant of the geographical region of Great Britainhttp://www.thefreedictionary.com/Briton Definition of Briton. The Free Dictionary, The American Heritage Dictionary of the English Language, Fourth Edition 2000 by Houghton Mifflin Company. Updated in 2003.