Hypogeum \Hyp`o*ge"um\, n.; pl. {Hypogea}. [L., fr. Gr. ?, ?, subterranean; ? under + ?, ?, the earth.] (Anc. Arch.) The subterraneous portion of a building, as in amphitheaters, for the service of the games; also, subterranean galleries, as the catacombs.