Hypogeum
Pronunciation : Hyp`o*ge"um
Part of Speech : n.;
Etymology : [L., fr. Gr. (Anc. Arch.)
Definition : Defn: The subterraneous portion of a building, as in amphitheaters, for the service of the games; also, subterranean galleries, as the catacombs.
pl. Hypogea.
Source : Webster's Unabridged Dictionary, 1913