(Ζηΐλας), son of Nicomedes, king of Bithynia, and Ditizele. In consequence of the intrigues of his step-mother, Etazeta, Zeilas was compelled to take refuge with the king of Armenia. At his death Nicomedes left his throne to his children by Etazeta, to the exclusion of Zeilas, who immediately endeavored to regain his rights by force. After several battles, fought with various success, he recovered the throne, probably about B. C. 250. He was succeeded by his son Prusias about B. C. 228. (Memnon, ap. Phot. Cod. 224, p. 228, ed. Bekker; Clinton, Fasti Hellen. vol. iii. p. 413.)