Lewis Short
prīmĭvirgĭus (noun M) : primus-virga
* One who carries the rod first before the king, head verger: πρωτοραβδοῦχος, primivirgius, Gloss. Gr. Lat.: primivirgius, caballarius, quod primus est militiae in virgis, Gloss. Isid.
Charlton T. Lewis, Charles Short, A Latin Dictionary