Great Britain vs pointsman

Great Britain and pointsman both are nouns.

Word	Noun	Adjective	Verb	Adverb
Great Britain	Yes	No	No	No
pointsman	Yes	No	No	No

Great Britain (noun)	pointsman (noun)
an island comprising England and Scotland and Wales	a policeman stationed at an intersection to direct traffic
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