nightfall vs evenfall

nightfall and evenfall both are nouns.

Word	Noun	Adjective	Verb	Adverb
nightfall	Yes	No	No	No
evenfall	Yes	No	No	No

As nouns, nightfall and evenfall are synonyms defined as:

Other synonyms of nightfall include crepuscle, crepuscule, dusk, fall, gloam, gloaming, twilight.

nightfall (noun)	evenfall (noun)
the time of day immediately following sunset	the time of day immediately following sunset