gruel (n.)
late 12c., "meal or flour made of beans, lentils, etc.," from Old French gruel "fine meal," from Frankish *grut (cognate with Middle Dutch grute "coarse meal, malt;" Middle High German gruz "grain"), from PIE *ghreu- "to rub, grind" (see grit). Meaning "thin porridge or soup" is late 14c.