An Etymological Dictionary of the German Language/lüpfen
lüpfen, ‘to set free and then raise aloft,’ an UpG. vb., from the equiv. MidHG. lüpfen, lupfen. Since the word is not found in other languages (Goth. *luppjan?), its origin cannot be discovered; perhaps it is connected with the cognates of Läufel. In ModHG. a modern vb., lüften (allied to Luft), ‘to lift,’ has supplanted the cognate phonetic form lüpfen.