night vs crepuscle

night and crepuscle both are nouns.

Word	Noun	Adjective	Verb	Adverb
night	Yes	No	No	No
crepuscle	Yes	No	No	No

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

Other hypernyms of night include crepuscule, dusk, evenfall, fall, gloam, gloaming, nightfall, twilight.

night (noun)	crepuscle (noun)
darkness	the time of day immediately following sunset
the time after sunset and before sunrise while it is dark outside
a period of ignorance or backwardness or gloom
the dark part of the diurnal cycle considered a time unit
the time between sunset and midnight
the period spent sleeping
a shortening of nightfall