green paper vs Britain

green paper and Britain both are nouns.

Word	Noun	Adjective	Verb	Adverb
green paper	Yes	No	No	No
Britain	Yes	No	No	No

green paper (noun)	Britain (noun)
a preliminary report of government proposals that is published in order to stimulate discussion	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