Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
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.