A native of Great Britain.

an inhabitant of southern Britain prior to the Anglo-saxon invasions

characteristic of or associated with the Britons; "the Briton inhabitants of England"

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.