An Etymological Dictionary of the German Language/Spreu
Spreu, f., ‘chaff,’ from the equiv. MidHG. and OHG. spriu (gen. spriuwes), n. A specifically HG. word, which, like MidHG. sprœwen, MidDu. spraeien (Goth. *sprêwjan), ‘to emit sparks, fly as dust, scatter,’ is based on a Teut. and an Aryan root sprē̆w, ‘to emit sparks,’ of which, however, no further traces can be found (see further sprühen). The corresponding LG. word is represented by the cognates, E. chaff and Du. kaf.