sepulchre vs burial chamber

sepulchre and burial chamber both are nouns.

Word	Noun	Adjective	Verb	Adverb
sepulchre	Yes	No	No	No
burial chamber	Yes	No	No	No

As nouns, sepulchre and burial chamber are synonyms defined as:

Other synonyms of sepulchre include sepulcher, sepulture.

sepulchre (noun)	burial chamber (noun)
a chamber that is used as a grave	a chamber that is used as a grave