Lewis & Short

Ēĕtĭon, ōnis, m., = Ἠετίων, the father of Andromache, and king of Thebe, in Cilicia, Ov. Tr. 5, 5, 44; id. F. 4, 280.
Hence, Ēĕtĭōnēus, a, um, pertaining to Eëtion: Thebae, Ov. M. 12, 110.