Lewis Short
ăgāso (noun M) : ago, as Sanscr. agas from ag; v. ago
* A driver, but esp. one who drives and takes care of horses, a hostler, groom, Plaut. Merc. 5, 2, 11: duo equi cum agasonibus,Liv. 43, 5: agasonem cum equo,Plin. 35, 11, 40, n. 29.
* Contemptuously, a low servant, lackey: si patinam frangat agaso,Hor. S. 2, 8, 72; Pers. 5, 76.
Charlton T. Lewis, Charles Short, A Latin Dictionary