THESAURUS (Gr. B17o-avp6s)  , the term in architecture given to the Greek treasure house, and at one time applied to the beehive tombs of Mycenae and other parts of Greece, now recognized as tombs; the subterranean chambers under some of the Greek temples were probably used as treasure rooms . Sometimes in the rear of the cella of a Greek temple there was a chamber, known as the opisthodomus, in which the treasures were kept; and, failing this provision, the epinaos or rear portico of the temple was enclosed with large railings and utilized for the same purpose; in this case the term opisthodomus was applied to it . " Thesaurus " is also used of a dictionary, or lexicon, as being a " treasure house " or store of knowledge .