UK vs Special Air Service

UK and Special Air Service both are nouns.

Word	Noun	Adjective	Verb	Adverb
UK	Yes	No	No	No
Special Air Service	Yes	No	No	No

UK (noun)	Special Air Service (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	a specialist regiment of the British army that is trained in commando techniques of warfare and used in clandestine operations (especially against terrorist groups)