noun, masculine/ka.vo/plural: caveaux
crypt, sepulchre; a small cellar used to store wines and liquors; a dark place, place without light; a subterranean club, café, cabaret; a dug-out or sod hut
“Sous cette chapelle était le caveau de telle famille.” — Under this chapel is the crypt of the family.
From cave + -eau. From Old French caviau.