ἀτρεής
From LSJ
Ἀμήχανον δὲ παντὸς ἀνδρὸς ἐκμαθεῖν ψυχήν τε καὶ φρόνημα καὶ γνώμην πρὶν ἂν ἀρχαῖς τε καὶ νόμοισιν ἐντριβὴς φανῇ → It is impossible to know the spirit, thought, and mind of any man before he be versed in sovereignty and the laws
English (LSJ)
ές,
A = ἄτρεστος: acc. ἀτρέα for ἀτρεέα, Euph.125; also, not to be feared, pl., ἀτρεῖες (for ἀτρεέες) ἀνάγκαι IG14.1389ii 18.