stockbroker belt vs Britain

stockbroker belt and Britain both are nouns.

Word	Noun	Adjective	Verb	Adverb
stockbroker belt	Yes	No	No	No
Britain	Yes	No	No	No

stockbroker belt (noun)	Britain (noun)
a wealthy residential suburb	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