An Etymological Dictionary of the German Language/Annotated/Rotz

Rotz, masculine, ‘mucus, snot,’ from the equivalent Middle High German roz, rotz, Old High German roz, earlier hroz, masculine and neuter, formed from a Teutonic root hrū̆t (Aryan krud); compare Old High German rûȥan, Anglo-Saxon hrûtan, ‘to snore, snort,’ Old Icelandic hrjóta. It can scarcely be compared with Greek κόρυζα, ‘cold, catarrh.’