FromProto-Celtic*awontro (compareCornishewnter), oblique of*awontīr (compareWelshewythr), from pre-Celtic*h₂eu-on-tēr, fromProto-Indo-European*h₂ewh₂-(“relative, descendant”),*h₂éwh₂os (compareMiddle Irishó,Latinavus(“grandfather”), dialectal GermanAwwe).