s. atrium (originally the sitting-room of a Roman house; afterward, in wealthy houses, it was distinct from the private apartments, and used as a great reception room, where the patron received his clients, and the great the morning visits of their friends and dependents; it was also, like our “hall,” the name of certain large public buildings, from the similarity of their construction to that of the atrium of a house. ☞ The vestibulum was an open space or court before the door, surrounded on three sides by the house: exedra, ἐξέδρα, was a room for the reception of company, the two extremities of which terminated in a semicircle, with a circular bench; it was uncovered; Vid: Vitr., 7, 5, 2, and 7, 9, 2). A small hall, atriolum.