ἀτυράννευτος
From LSJ
εἰ ἀποκρυπτόντων τῶν Μήδων τὸν ἥλιον ὑπὸ σκιῇ ἔσοιτο πρὸς αὐτοὺς ἡ μάχη καὶ οὐκ ἐν ἡλίῳ → if the Medes hid the sun, the battle would be to them in the shade and not in the sun
English (LSJ)
ον,
A not ruled by tyrants, free from tyrants, Th.1.18, D.C.37.22, Chor.p.208B.:—also ἀτύραννος, ον, Phryn.PSp.30B.
German (Pape)
[Seite 390] nicht von Tyrannen beherrscht, Thuc. 1, 18.