An Etymological Dictionary of the German Language/Knappe
Knappe, m., ‘squire, attendant,’ from MidHG. knappe, m., ‘youth, bachelor, servant, squire,’ OHG. chnappo, m.; in the rest of the OTeut. languages there are no cognates pointing to Goth. *knabba; two variants of the assumed *knabba are mentioned under Knabe, where the further etymological question is discussed. Comp. also Nabe with Nappe, Goth. laigân, ‘to lick,’ with AS. liccian.