ὑποστορεννύναι
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
Greek > English (Woodhouse Verbs Reversed)
spread under, stretch under, strew under (see also: ὑποστόρνυμι)