Orchestra, huius orchestræ, f. g. Cic.A place wherein Senatours and noble persons sate to behold playes: sometime the sessious of the Senate.
Lewis and Short: Latin dictionary
orchēstra, ae, f., = o)rxh/stra. I.The place where the Senate sat in the theatre, the orchestra: in orchestrā senatorum sunt sedibus loca destinata, Vitr. 5, 6; Juv. 7, 47; Suet. Caes. 39; id. Aug. 35; 44; id. Claud. 21 et saep.—B.Transf., the Senate (poet.): similesque videbis Orchestram et populum, Juv. 3, 178.—II.Another place on the stage, acc. to Fest. p. 181 b; cf. Müll. ad h. l.