An Etymological Dictionary of the German Language/Annotated/Horn
Horn, neuter, ‘horn, peak,’ from the equivalent Middle High German and Old High German horn, neuter; compare Gothic haúrn, Old Icelandic horn, Anglo-Saxon and English horn, Old Frisian horn, Dutch horen; a common Teutonic word for ‘horn,’ cognate with Latin cornu, and Irish, Welsh, and Cornish corn (κάρνον την σάλπιγγα Τάλατας, Hesychius); allied to Greek κέρ-ας, ‘horn,’ with a different suffix (compare also Teutonic Hirsch, literally ‘horned animal’), as well as the equivalent Sanscrit çrñ-ga. See further respecting the Aryan root ker under Hirn. Compare Hahnrei.