Great Britain vs privy council

Great Britain and privy council both are nouns.

Word	Noun	Adjective	Verb	Adverb
Great Britain	Yes	No	No	No
privy council	Yes	No	No	No

Great Britain (noun)	privy council (noun)
an island comprising England and Scotland and Wales	an advisory council to a ruler (especially to the British Crown)
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