guest night vs Britain

guest night and Britain both are nouns.

Word	Noun	Adjective	Verb	Adverb
guest night	Yes	No	No	No
Britain	Yes	No	No	No

guest night (noun)	Britain (noun)
an evening when members of a club or college can bring their friends as guests	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