An Etymological Dictionary of the German Language/Annotated/Kolben
Kolben, masculine, ‘club,’ from Middle High German kolbe, ‘mace, club, cudgel,’ Old High German cholbo, masculine; Icelandic kólfr, masculine, ‘javelin, arrow, bulb,’ with the derivative kylfi, neuter, kylfa, feminine, ‘club, cudgel.’ Gothic *kulba-n-, ‘stick with a thick knob at the end.’ From its meaning the word seems to be related to the cognates with the nasal form klumb, discussed under Klumpen; in that case the Aryan root may be gl-bh, and the word compared with Latin globus, ‘round mass’ (also ‘clique,’ compare English club).