public house vs UK

public house and UK both are nouns.

Word	Noun	Adjective	Verb	Adverb
public house	Yes	No	No	No
UK	Yes	No	No	No

public house (noun)	UK (noun)
tavern consisting of a building with a bar and public rooms; often provides light meals	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