I.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.—
II. Contemptuously, a low servant, lackey: “si patinam frangat agaso,” Hor. S. 2, 8, 72; Pers. 5, 76.