mere vs United Kingdom of Great Britain and Northern Ireland

mere and United Kingdom of Great Britain and Northern Ireland both are nouns.

Word	Noun	Adjective	Verb	Adverb
mere	Yes	Yes	No	No
United Kingdom of Great Britain and Northern Ireland	Yes	No	No	No

mere (noun)	United Kingdom of Great Britain and Northern Ireland (noun)
a small pond of standing water	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

mere (adjective)	United Kingdom of Great Britain and Northern Ireland (adjective)
apart from anything else; without additions or modifications
being nothing more than specified