unratable vs Great Britain

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

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

unratable (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

unratable (adjective)	Great Britain (adjective)
not subject to locally assessed property taxes