Remembrance Sunday vs United Kingdom of Great Britain and Northern Ireland

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

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

Remembrance Sunday (noun)	United Kingdom of Great Britain and Northern Ireland (noun)
the Sunday nearest to November 11 when those who died in World War I and World War II are commemorated	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