Lewis Short
campÄ-doctor (noun M) : (better as two words), , id.
* One who drills or exercises soldiers in the Campus Martius, a drill-master, Veg. Mil. 3, 6; 3, 8; 1, 13; Lampr. Alex. Sev. 53; Amm. 15, 3, 10; Inscr. Orell. 1790; 3495.
Charlton T. Lewis, Charles Short, A Latin Dictionary