The Collaborative International Dictionary of English v.0.48:

Psilopaedes \Psi`lo*p[ae]"des\, n. pl. [NL., from Gr.? bare + ?,
   ?, offspring.] (Zool.)
   birds whose young at first have down on the pteryl[ae] only;
   -- called also Gymnop[ae]des.
   [1913 Webster]