eventide vs evening

eventide and evening both are nouns.

Word	Noun	Adjective	Verb	Adverb
eventide	Yes	No	No	No
evening	Yes	No	No	No

As nouns, eventide and evening are synonyms defined as:

eventide and evening: the latter part of the day (the period of decreasing daylight from late afternoon until nightfall)

Other synonyms of eventide include eve, even.

eventide (noun)	evening (noun)
the latter part of the day (the period of decreasing daylight from late afternoon until nightfall)	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