Source : Webster's Revised Unabridged Dictionary (1913)

Eyas \Ey`as\, n. [F. niais fresh from the nest, a derivative fr.
   L. nidus nest. E. an eyas for a nias. See {Nest}, and cf.
   {Nias}, {Jashawk}.] (Zo["o]l.)
   A nesting or unfledged bird; in falconry, a young hawk from
   the nest, not able to prey for itself. --Shak J. H. Walsh

Eyas \Ey"as\, a.
   Unfledged, or newly fledged. [Obs.]

         Like eyas hawk up mounts unto the skies, His newly
         budded pinions to assay.                 --Spebser.

Source : WordNet®

eyas
     n : an unfledged or nestling hawk