don vs UK

don and UK both are nouns.

Word	Noun	Adjective	Verb	Adverb
don	Yes	No	Yes	No
UK	Yes	No	No	No

don (noun)	UK (noun)
teacher at a university or college (especially at Cambridge or Oxford)	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 head of an organized crime family

don (verb)	UK (verb)
put clothing on one's body