An Etymological Dictionary of the German Language/Annotated/riechen

by Friedrich Kluge

riechen, verb, ‘to smell,’ from Middle High German riechen, Old High German riohhan, strong verb, ‘to smoke, steam, emit vapour, smell’; compare Dutch ruiken, rieken, ‘to smell,’ Anglo-Saxon reócan, ‘to smoke, emit vapour,’ Old Icelandic rjúka, ‘to smoke, exhale.’ The Teutonic root rū̆k signified ‘to smoke’; see further under Rauch and Geruch. In the non-Teutonic languages the stem is not found.