Late 15th century (in an earlier sense). From Middle French alerion, allerion (French alérion) mythical large bird without feet, resembling an eagle, heraldic representation of a bird with neither feet nor beak from an (unattested) Old Low Franconian form ultimately cognate with Middle Dutch adelaer, adeler (Dutch adelaar), Middle Low German adeler, Old High German adalaro (Middle High German adelar, adeler, adler, German Adler), all in sense ‘eagle’, all from the Germanic base of athel + the Germanic base of erne, the eagle receiving the epithet ‘noble’ in recognition of its majestic appearance and its widespread use in hunting.