An Etymological Dictionary of the German Language/Annotated/Ohm

Ohm, masculine and masculine, ‘awm’ (liquid measure, about 40 galls.), from Middle High German âme, ôme (â before nasals is changed into ô, compare Mohn, Mond, Ohmet, and ohne), feminine, masculine, and neuter, ‘awm, measure’; corresponding to Dutch aam, English awm, Scandinavian áma. They are based on Middle Latin ama, ‘vessel, wine measure’ (Greek ἄχη, ‘water-pail,’ Latin ama, ‘water bucket’). See ahmen.