Lewis Short
circĕs (noun M) : circum-ire
* A circle (ante- and post-class.): ut parvi circuli Anuli, sic magni dicebantur circites Ani, Varr L. L. 6, § 8 Müll.; Sid. Carm. 22, 222. —So of the circumference of the circus, Sid. Carm. 23, 381.
Charlton T. Lewis, Charles Short, A Latin Dictionary