GRIND v. 2 definitions
To wear down, polish, or sharpen, by friction; to make smooth, sharp, or pointed; to whet, as a knife or drill; to rub against one another, as teeth, etc.
GRINDSTONE n.
at, circular stone, revolving on an axle, for grinding or sharpening tools, or shaping or smoothing objects. To hold, pat, or bring one's nose to the grindstone, to oppress one; to keep one in a condition of servitude. They might be ashamed, for lack of courage, to suffer the Lacedæmonians to hold their noses to the gr…