ἀκηρυκτεί
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)
and ἀκηρ-υκτί, Adv.
A without flag of truce, ἐπιμείγνυσθαι Th. 2.1; πολεμεῖν D.C.50.7.