ratable vs Great Britain

ratable is not a noun while Great Britain is a noun.

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

ratable (noun)	Great Britain (noun)
	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

ratable (adjective)	Great Britain (adjective)
liable to payment of locally assessed property taxes