LSJ
ίδος, horned, of Io, A. Pr. 674. as Subst., horned serpent or asp, Cerastes cornutus, Nic. Th. 258, LXX Pr. 23.32, D.S. 3.50, Ael. NA 1.57.
Liddell-Scott-Jones, Greek-English Lexicon (9th ed., 1940)
Pape
ίδος, ἡ, fem. zu κεραστής, Arcad. p. 35.19.
Pape, Griechisch-deutsches Handwörterbuch (3. Aufl., 1914)