in antiquity, a great building of a round or oval figure, erected by the ancients, to exhibit shows to the people. See CIRCENSIAN Games.

The Roman circus was a large oblong edifice, archied at one end, encompassed with porticoes, and furnished with two rows of seats, placed ascending over each other. In the middle was a kind of foot-bank, or eminence, with obelisks, statues, and posts at each end. This served them for the courses of their bigae and quadrigae.

Those that have measured the circus say, that it was 2187 feet long, and 960 broad; to that it was the greatest building in Rome: some say it would contain 150,000 people, other 260,000, or 300,000.