Hypogeum

• (n.) The subterraneous portion of a building, as in amphitheaters, for the service of the games; also, subterranean galleries, as the catacombs.
Found on http://thinkexist.com/dictionary/meaning/hypogeum/

Hypogeum

Hyp`o·ge'um noun ; plural Hypogea . [ Latin , from Greek ..., ..., 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.
Found on http://www.encyclo.co.uk/webster/H/83

hypogeum

In archaeology, an underground chamber used as a burial place. With varying construction, they may be dug from the earth; cut from rock, as in the Roman catacombs; or built of masonry, as at...
Found on http://www.encyclo.co.uk/local/20688

hypogeum

underground chamber
Found on http://phrontistery.info/h.html
No exact match found