tavern keeper vs Great Britain

tavern keeper and Great Britain both are nouns.

Word	Noun	Adjective	Verb	Adverb
tavern keeper	Yes	No	No	No
Great Britain	Yes	No	No	No

tavern keeper (noun)	Great Britain (noun)
the keeper of a public house	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