crypt vs sepulchre

crypt and sepulchre both are nouns.

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

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

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

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

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