Great Britain vs lumber room

Great Britain and lumber room both are nouns.

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

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