An Etymological Dictionary of the German Language/Annotated/Kampf
Kampf, masculine, ‘combat,’ from Middle High German kampf, masculine and neuter, ‘combat, duel, tilting’; Old High German champf, masculine, Anglo-Saxon camp, comp; Old Icelandic kapp, neuter. The Old Icelandic word is interesting, because it signifies literally ‘zeal, emulation,’ which is the original meaning of Kampf (Modern High German Krieg has gone through a similar development of meaning). Hence there is no probability in the assumption that Old Teutonic *kampa- is derived from Latin campus, thus connecting it with Campus Martius. This older assumption receives no support from phonetic laws, for kamp does not look unlike a Teutonic word, while the meaning of the Scandinavian word makes it impossible. We should consider, too, whether the old Teutons, with their numerous terms relating to war, had any need of borrowing such a word. Some connect Old Teutonic kampo- with Sanscrit jañg, ‘to fight.’ High German Kämpfer, and Kämpfe, Kämpe, properly ‘combatant,’ is Middle High German kęmpfe, Old High German chęmphio, ‘wrestler, duellist’; Anglo-Saxon cęmpa, and Old Icelandic kappe signify ‘warrior, hero’; this term, denoting the agent, passed into Romance (compare French champion, whence also English champion).