Security Service vs United Kingdom

Security Service and United Kingdom both are nouns.

Word	Noun	Adjective	Verb	Adverb
Security Service	Yes	No	No	No
United Kingdom	Yes	No	No	No

Security Service (noun)	United Kingdom (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