United Kingdom of Great Britain and Northern Ireland vs speech day

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

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

United Kingdom of Great Britain and Northern Ireland (noun)	speech day (noun)
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	an annual day in the schools when speeches are made and prizes are distributed