Great Britain vs fire watcher

Great Britain and fire watcher both are nouns.

Word	Noun	Adjective	Verb	Adverb
Great Britain	Yes	No	No	No
fire watcher	Yes	No	No	No

Great Britain (noun)	fire watcher (noun)
an island comprising England and Scotland and Wales	(during World War II in Britain) someone whose duty was to watch for fires caused by bombs dropped from the air
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