Great Britain vs first-class honours degree

Great Britain and first-class honours degree both are nouns.

Word	Noun	Adjective	Verb	Adverb
Great Britain	Yes	No	No	No
first-class honours degree	Yes	No	No	No

Great Britain (noun)	first-class honours degree (noun)
an island comprising England and Scotland and Wales	an honours degree of the highest class
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