billion vs United Kingdom of Great Britain and Northern Ireland

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

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

billion (noun)	United Kingdom of Great Britain and Northern Ireland (noun)
the number that is represented as a one followed by 9 zeros	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
the number that is represented as a one followed by 12 zeros; in the United Kingdom the usage followed in the United States is frequently seen
a very large indefinite number (usually hyperbole)

billion (adjective)	United Kingdom of Great Britain and Northern Ireland (adjective)
denoting a quantity consisting of one thousand million items or units in the United States
denoting a quantity consisting of one million million items or units in Great Britain