guest night vs evening

guest night and evening both are nouns.

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

As nouns, evening is a hypernym of guest night; that is, evening is a word with a broader meaning than guest night:

guest night: an evening when members of a club or college can bring their friends as guests
evening: the latter part of the day (the period of decreasing daylight from late afternoon until nightfall)

Other hypernyms of guest night include eve, even, eventide.

guest night (noun)	evening (noun)
an evening when members of a club or college can bring their friends as guests	the latter part of the day (the period of decreasing daylight from late afternoon until nightfall)
	a later concluding time period
	the early part of night (from dinner until bedtime) spent in a special way