Lewis & Short

Ĕtĕōclēs, is and ĕos, m., = Ἐτεοκλῆς,

  1. I. son of Oedipus and Jocasta, brother of Polynices; he was the cause of the Theban war, described by the Roman poet Statius in the Thebais, Cic. Off. 3, 21, 82; Hyg. Fab. 76; gen. Eteoclis, Stat. Th. 3, 214: Eteocleos, id. ib. 12, 421; acc. Eteoclea, id. ib. 7, 688.
    Hence,
  2. II. Ĕtĕōclēus, a, um, adj., of Eteocles: contentiones, App. M. 10, p. 245, 30.