An Etymological Dictionary of the German Language/Ruhr

by Friedrich Kluge

Ruhr, f., ‘stir, disorder, diarrhœa, dysentery,’ from the equiv. MidHG. ruor, ruore, f., lit. ‘violent, hasty motion’; allied to rühren; comp. MidHG. ruortranc, ‘purgative.’ The general meaning ‘‘violent motion’ is still preserved in the compound Aufruhr, ‘riot.’