crepuscule vs nightfall

crepuscule and nightfall both are nouns.

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

As nouns, crepuscule and nightfall are synonyms defined as:

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

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