high tea vs Great Britain

high tea and Great Britain both are nouns.

Word	Noun	Adjective	Verb	Adverb
high tea	Yes	No	No	No
Great Britain	Yes	No	No	No

high tea (noun)	Great Britain (noun)
substantial early evening meal including tea	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