"sea eagle," from Old English earn "eagle," a common Germanic word (cf. Old High German arn, German Aar, Middle Dutch arent, Old Norse örn, Gothic ara "eagle"), from PIE root *or- "great bird, eagle" (cf. Greek ornis "bird," Old Church Slavonic orilu, Lithuanian erelis, Welsh eryr "eagle"). The Germanic word also survives in the first element of old Germanic names such as Arnold and Arthur.