Great Britain vs Battle of Britain

Great Britain and Battle of Britain both are nouns.

Word	Noun	Adjective	Verb	Adverb
Great Britain	Yes	No	No	No
Battle of Britain	Yes	No	No	No

Great Britain (noun)	Battle of Britain (noun)
an island comprising England and Scotland and Wales	the prolonged bombardment of British cities by the German Luftwaffe during World War II and the aerial combat that accompanied it
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