Prōteus (dissyl.), ĕi and ĕos, m., = Πρωτεύς, a sea-god who often changed his form; he was in the service of Neptune, and kept his sea-calves, Ov. M. 8, 731; 2, 9; id. A. A. 1, 761; Hor. C. 1, 2, 7; Verg. G. 4, 388; Ov. F. 1, 367: Protei columnae, i. e. the boundary of Egypt, Verg. A. 11, 262.
Transf., of a fickle person: Protea tenere, Hor. Ep. 1, 1, 90; of a cunning person, id. S. 2, 3, 71; cf. Amm. 29, 1, 39.