Source : Webster's Revised Unabridged Dictionary (1913)

Roughleg \Rough"leg`\, n. (Zo["o]l.)
   Any one of several species of large hawks of the genus
   {Archibuteo}, having the legs feathered to the toes. Called
   also {rough-legged hawk}, and {rough-legged buzzard}.

   Note: The best known species is {Archibuteo lagopus} of
         Northern Europe, with its darker American variety
         ({Sancti-johannis}). The latter is often nearly or
         quite black. The ferruginous roughleg ({Archibuteo
         ferrugineus}) inhabits Western North America.