burial vault(n = noun.artifact) vault - a burial chamber (usually underground);
is a kind of burial chamber, sepulcher, sepulchre, sepulture
has particulars: charnel, charnel house, columbarium

bank vault, barrel vault, burial, burial chamber, burial garment, burial ground, burial mound, burial site, groined vault, pole vault, ribbed vault, sky burial, tree burial, vault, vault of heaven