crypt vs sepulture

crypt and sepulture both are nouns.

Word	Noun	Adjective	Verb	Adverb
crypt	Yes	No	No	No
sepulture	Yes	No	No	No

As nouns, sepulture is a hypernym of crypt; that is, sepulture is a word with a broader meaning than crypt:

crypt: a cellar or vault or underground burial chamber (especially beneath a church)
sepulture: a chamber that is used as a grave

Other hypernyms of crypt include burial chamber, sepulcher, sepulchre.

crypt (noun)	sepulture (noun)
a cellar or vault or underground burial chamber (especially beneath a church)	a chamber that is used as a grave
	the ritual placing of a corpse in a grave