柯林斯词典grindstone /ˈɡraɪndˌstəʊn/ (grindstones) 1. N-COUNT A grindstone is a large, round stone that turns like a wheel and is used for sharpening knives and tools. 砂轮 返回 grindstone剑桥词典a large , round stone that is turned by a machine and is used to make tools sharper or sharp edges smooth 磨石，砂轮 返回 grindstone