in the Grecian theatres, was that part of the proscenium or stage where the chorus used to dance. In the middle of it was placed the Aorion or pulpit. The orchestra was semicircular, and surrounded with seats. In the Roman theatres it made no part of the scena, but answered pretty nearly to the pit in our playhouses, being taken up with seats for senators, magistrates, vestals, and other persons of distinction. The actors never went down into it. See THEATRE.

ORCHIA T E X, instituted by Orchius the tribune in the year of Rome 566. Its intention was to limit the number of guests that were to be admitted at an entertainment; and it also enforced, that during supper, which was the chief meal among the Romans, the doors of every house should be left open.