An Etymological Dictionary of the German Language/Annotated/Spreu
Spreu, feminine, ‘chaff,’ from the equivalent Middle High German and Old High German spriu (genitive spriuwes), neuter A specifically High German word, which, like Middle High German sprœwen, Middle Dutch spraeien (Gothic *sprêwjan), ‘to emit sparks, fly as dust, scatter,’ is based on a Teutonic and an Aryan root sprē̆w, ‘to emit sparks,’ of which, however, no further traces can be found (see further sprühen). The corresponding Low German word is represented by the cognates, English chaff and Dutch kaf.