United Kingdom of Great Britain and Northern Ireland vs pelican crossing

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

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

United Kingdom of Great Britain and Northern Ireland (noun)	pelican crossing (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 acronym for pedestrian light control; a pedestrian crossing with traffic lights that are controlled by pedestrians