LSJ
ον, = ὀνοσκελίς, of the hobgoblin Empusa, Sch. Ar. Ra. 296 ; — also ὀνόκωλις, ἡ, Eust. 1704.42.
Liddell-Scott-Jones, Greek-English Lexicon (9th ed., 1940)
Pape
eselsfüßig, Schol. Ar. Ran. 295.
Pape, Griechisch-deutsches Handwörterbuch (3. Aufl., 1914)