Security Service vs United Kingdom of Great Britain and Northern Ireland

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

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

Security Service (noun)	United Kingdom of Great Britain and Northern Ireland (noun)
the government agency in the United Kingdom that is responsible for internal security and counterintelligence on British territory	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