1. A rhetorician frequently mentioned by the elder Seneca. He was the author of a work on that branch of rhetoric entitled colores (respecting the meaning of which see Quint. Inst. 4.2.88). Through the influence of Sejanus, Otho was made a senator, and by due subservience to the ruling powers, he obtained the praetorship in A. D. 22, in which year he is mentioned as one of the accusers of C. Silanus, proconsul of Asia. (Senec. Control. 1.3, Declam.2.1, &c.; Tac. Ann. 3.66.)