LSJ
ὁ, (< κοέω) sheep-minded, i.e.
simpleton, Ar. Eq. 264.
Liddell-Scott-Jones, Greek-English Lexicon (9th ed., 1940)
Pape
ὁ (κοέω), Ar. Eq. 264, schafsinnig, Schol. προβατώδης, μῶρος καὶ εὐήθης.
Pape, Griechisch-deutsches Handwörterbuch (3. Aufl., 1914)