διάρτισις
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)
εως, ἡ,
A moulding, shaping, EM361.8, Suid.; composition, prob. l. for διάρτησις, Gal.15.102.
German (Pape)
[Seite 601] ἡ, Gestaltung, VLL.