n. (Zool.) 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. [ 1913 Webster ]

☞ 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. [ 1913 Webster ]