An Etymological Dictionary of the German Language/Annotated/Läufel

by Friedrich Kluge

Läufel, Lauft, ‘shell’ (especially nutshell), a Hessian and Franconian word, corresponding to Old High German louft, ‘nutshell, bark of trees.’ Prim. cognate with Lithuanian lupinai, ‘peel, skins of fruit’ (lùpti, ‘to skin, peel’), Polish lupina, ‘husk,’