Victoria plum vs Great Britain

Victoria plum and Great Britain both are nouns.

Word	Noun	Adjective	Verb	Adverb
Victoria plum	Yes	No	No	No
Great Britain	Yes	No	No	No

Victoria plum (noun)	Great Britain (noun)
a large red plum served as dessert	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