Definitions for "Soros"
(Gr., "relic," "chest"): reliquary chest. The term is closely related to two important Marian relics treasured in Constantinople: the mantle of the Virgin at the Blachernai Church, and the girdle of the Virgin, housed at the Chalkopratia Church. Both relics were stored in chapels, whose splendor mirrored those of small reliquary caskets, hence the conflation of the term typically used for a small chest for a large architectural structure.
Soros is also a settlement in the island of Antiparos, one of the Cyclades, see Soros (Antiparos), Greece