burial chamber vs vault

burial chamber and vault both are nouns.

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

As nouns, vault is a hyponym of burial chamber; that is, vault is a word with a more specific, narrower meaning than burial chamber:

Other hyponyms of burial chamber include crypt, mausoleum, monument, repository, burial vault.

burial chamber (noun)	vault (noun)
a chamber that is used as a grave	the act of jumping over an obstacle
	an arched brick or stone ceiling or roof
	a burial chamber (usually underground)
	a strongroom or compartment (often made of steel) for safekeeping of valuables

burial chamber (verb)	vault (verb)
	bound vigorously
	jump across or leap over (an obstacle)