Lewis & Short

ōrātus, ūs (only in abl. sing. and plur.), m. [oro], a praying, entreating; a request, entreaty (very rare but class.): oratu tuo, Cic. Fl. 37, 92: illarum oratu, Plaut. Cas. 2, 2, 17; Sid. Ep. 9, 14 init.: magnis oratibus, Coripp. Laud. Just. 2, 4.