lumber room vs Great Britain

lumber room and Great Britain both are nouns.

Word	Noun	Adjective	Verb	Adverb
lumber room	Yes	No	No	No
Great Britain	Yes	No	No	No

lumber room (noun)	Great Britain (noun)
a storeroom in a house where odds and ends can be stored (especially furniture)	an island comprising England and Scotland and Wales
	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