An Etymological Dictionary of the German Language/Kämpe
Kämpe, m., ‘combatant, wrestler,’ first introduced into literary ModHG. by the study of the Teut. languages, yet the special history of the word is not known. The form Indicates a LG. origin; comp. OLG. kęmpio, ‘combatant, warrior.’ Perhaps it was orig. a legal term of the Saxon Code. See Kampf.