Definition of British adjective from the Oxford Advanced Learner's Dictionary

British

adjective
ˈbrɪtɪʃ
 
; ˈbrɪtɪʃ
 
 
1 (abbr. Br.) connected with the United Kingdom of Great Britain and Northern Ireland or the people who live therethe British GovernmentHe was born in France but his parents are British.British-based/British-born/British-made2 the British noun [plural] the people of the United KingdomBritishness
ˈbrɪtɪʃnəs
 
; ˈbrɪtɪʃnəs
 
noun [uncountable]
Usage noteUsage note: the BritishThere is no singular noun which is commonly used to refer to a person from Britain. Instead the adjective British is used:She’s British. The British have a very odd sense of humour. The adjective English refers only to people from England, not the rest of the United Kingdom.The noun Briton is used mainly in newspapers:The survivors of the avalanche included 12 Britons. It also describes the early inhabitants of Britain:the ancient Britons. Brit is informal and can sound negative. Britisher is now very old-fashioned. note at Scottish