noun
- a hard, porous stone used as the upper or lower millstone in a mill for grinding grain
Usage: also spelled burr stone or burstone; historical/technical term
Examples
- The miller replaced the worn burrstone with a new one to improve the grinding quality.
- Burrstone was preferred for flour mills because of its durability and porous surface.
- The quarry supplied burrstone to mills throughout the region.
- Cracks in the burrstone reduced its effectiveness for milling.