An Etymological Dictionary of the German Language/Annotated/Granne
Granne, feminine, ‘bristle (of swine), awn,’ from Middle High German gran, grane, feminine, ‘point of hair, moustache, fish-bone’ (in the latter sense Granne is also used dialectic), Old High German grana, ‘moustache’; corresponding to Anglo-Saxon grǫnu, Old Icelandic grǫn, ‘moustache.’ To the Goth grana, recorded by Isidore, are due Spanish greña, ‘tousled hair,’ and Old French grenon, ‘moustache and whiskers.’ The Teutonic cognates are primitively allied to Old Irish grend, Gaelic greann, ‘moustache’ and ‘shaggy hair.’ See Grat.