Merriam-Webster Collegiate Dictionary - grist

 noun  Etymology: Middle English, from Old English grist; akin to Old English grindan to grind  Date: before 12th century  1.  a. grain or a batch of grain for grinding  b. the product obtained from a ~ of grain including the flour or meal and the grain offals  2. a required or usual amount  3. matter of interest or value forming the basis of a story or analysis  4. something turned to advantage or use — used especially in the phrase ~ for one's mill