Opisthodome

O‐pis″tho‐dome (?), n. [L. opisthodomus, Gr. �; ὄπισθεν behind + δόμοσ house: cf. F. opisthodome.] (Arch.) A back chamber; especially, that part of the naos, or cella, farthest from the main entrance, sometimes having an entrance of its own, and often used as a treasury.