top-flight vs Great Britain

top-flight is not a noun while Great Britain is a noun.

Word	Noun	Adjective	Verb	Adverb
top-flight	No	Yes	No	No
Great Britain	Yes	No	No	No

top-flight (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

top-flight (adjective)	Great Britain (adjective)
excellent; best possible