διὰ λαμπροτάτου βαίνοντες ἁβρῶς αἰθέρος → passing lightly through clear-shining air (Euripides, Medea 829)
subs.
P. μῖλαξ, ἡ (Plat.).
The word is also found in Eur., Bacch. 703, and Aristophanes, Nub. 1007, but apparently with a different meaning.