An Etymological Dictionary of the German Language/Annotated/Krüppel
Krüppel, masculine, ‘cripple,’ from the equivalent Middle High German krüppel, krüpel, masculine; it passed in the Middle High German period from Low German into High German; Dutch kreupel, English cripple, Middle English and Anglo-Saxon cryppel, Scandinavian kryppell, kryplingr. The p of these forms is High German pf (Alsatian Krüpfel), hence we must assume that High German Krüppel was borrowed from Low German and Middle German. Allied in the Upper German dialects to Swiss chrüft, chrüpfe, Suabian kropf, kruft, krüftle, Bavarian krapf, kropf, ‘deformed person,’ and the cognate Bavarian krüpfen, ‘to become crooked,’ akin to Old Icelandic kroppr, kryppa, ‘hump,’ and the cognates discussed under Kropf. Besides Greek γρυπός, ‘curved,’ we may also refer to Old Slovenian grŭbŭ, ‘back,’ ModSlov. grbanec, ‘wrinkle,’ Servian grba, ‘hump’ (grbati se, ‘to stoop’).