rag day vs Great Britain

rag day and Great Britain both are nouns.

Word	Noun	Adjective	Verb	Adverb
rag day	Yes	No	No	No
Great Britain	Yes	No	No	No

rag day (noun)	Great Britain (noun)
a day on which university students hold a rag	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