racing circuit vs Britain

racing circuit and Britain both are nouns.

Word	Noun	Adjective	Verb	Adverb
racing circuit	Yes	No	No	No
Britain	Yes	No	No	No

racing circuit (noun)	Britain (noun)
a racetrack for automobile races	a monarchy in northwestern Europe occupying most of the British Isles; divided into England and Scotland and Wales and Northern Ireland; `Great Britain' is often used loosely to refer to the United Kingdom