hўpŏgēus — Lewis & Short
hўpŏgēus, a, um, adj., = u(po/gaios,
I underground:
loca,Cael. Aur. Tard. 2, 37, 191.—Hence, subst.: hўpŏgēum or hў-pŏgaeum, i, n., = u(po/geion (u(po/gaion), a vault or cellar under ground, Vitr. 6, 11; a burying-vault, sepulchre, Petr. 111, 2; Inscr. Grut. 1114, 3.