L-plate vs United Kingdom of Great Britain and Northern Ireland

L-plate and United Kingdom of Great Britain and Northern Ireland both are nouns.

Word	Noun	Adjective	Verb	Adverb
L-plate	Yes	No	No	No
United Kingdom of Great Britain and Northern Ireland	Yes	No	No	No

L-plate (noun)	United Kingdom of Great Britain and Northern Ireland (noun)
a square plate bearing the letter L that is attached to both ends of a car to indicate that the driver is a learner	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