An Etymological Dictionary of the German Language/Annotated/Hornung

by Friedrich Kluge

Hornung, masculine, ‘February,’ from the equivalent Middle High German and Old High German hornunc(g); the termination -ung is patronymic; February is regarded as the offspring of January, which in earlier Modern High German (dialectic) is designated by großer Horn, ‘great horn,’ in contrast with February, kleiner Horn, ‘little horn.’ Compare Anglo-Saxon and Old Icelandic hornung, ‘bastard’?.