nightfall vs crepuscule

nightfall and crepuscule both are nouns.

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

As nouns, nightfall and crepuscule are synonyms defined as:

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

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