An Etymological Dictionary of the German Language/Annotated/kahl
kahl, adjective, from the equivalent Middle High German kal (genitive kalwer), ‘bald,’ Old High German chalo (genitive chalwêr, chalawêr); compare Dutch kaal, Anglo-Saxon calu, English callow. Probably borrowed from Latin calvus (Sanscrit khalvâta, ‘bald-headed’), whence French chauve, since Latin crispus and capillare have also been introduced into Teutonic; compare Anglo-Saxon cyrsp, English crisp, Old High German and Middle High German krisp, ‘curly,’ and Gothic kapillôn, ‘to crop one's hair.’ Probably the Teutons and the Romans were equally struck by each other's method of wearing the hair. Other etymologists are inclined to connect Teutonic kalwa- with Old Slovenian golŭ, ‘bare, naked.’