An Etymological Dictionary of the German Language/Annotated/Ahn

Ahn, masculine, ‘grandfather, ancestor,’ from Middle High German ane (collateral modified form ene), Old High German ano, masculine, ‘grandfather’; akin to the Alemannian diminutive Ähni, ‘grandfather.’ Further Modern High German Ahne, Middle High German ane, Old High German ana, feminine, ‘grandmother.’ To these are allied Modern High German Urahn, Middle High German urane, urene, Old High German *urano, masculine, great-grandfather'; in Old High German alt-ano, altar-ano (for the force of ur- in Urahne see ur-). The class is peculiar to German, being foreign to the remaining Teutonic dialects; compare also Enkel — really a diminutive form — which belongs to it. There is no doubt that Latin ănus, ‘old woman,’ is a primitively cognate. Perhaps the Teutonic masculine name Old High German Anelo (Anglo-Saxon Onela, Old Icelandic Ále) is allied to it.