An Etymological Dictionary of the German Language/Annotated/Kämpe
Kämpe, masculine, ‘combatant, wrestler,’ first introduced into literary Modern High German by the study of the Teutonic languages, yet the special history of the word is not known. The form Indicates a Low German origin; compare Old Low German kęmpio, ‘combatant, warrior.’ Perhaps it was originally a legal term of the Saxon Code. See Kampf.