Lewis Short
exercĭtĭum (noun N) : id.
* Exercise (postAug.; not in Cic. and Caes.): frequentibus exercitiis praeparare milites ad proelia, Sall. Fragm. ap. Veg. Mil. 1, 9 fin.: equitum,Tac. A. 2, 55; cf. Vell. 2, 109: aliarum quoque rerum vel studio vel exercitio eum teneri,Gell. 3, 1, 12: in exercitiis disci,i. e. plays,Vulg. 2 Macc. 4, 14.
Charlton T. Lewis, Charles Short, A Latin Dictionary