hypogeum
Could not find hypogaeo in Logeion dictionaries.
hypogaeo Noun: neuter dative singular, Noun: neuter ablative singular of hypogeum
hypogēum, ī, n. (ὑπόγειον), ein unterirdisches Gewölbe, Kellergeschoß, Vitr. 6, 8, 1. Vgl. hypogaeum.
hўpŏgēum, ī, n. (ὑπόγειον), construction souterraine, cave : Vitr. Arch. 6, 11 || caveau [pour les morts], hypogée : Petr. 111, 2.