ψύδραξ
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)
ᾰκος, ἡ
A, οἱ Ἴωνες ψύδρακας λέγουσι τὰς ποικίλας· ὅθεν καὶ ἡμεῖς ψύδρακας καλοῦμεν τὰ ἐπὶ τοῦ σώματος ἐξανθήματα EM819.10.