grind To break and reduce to fine particles by pounding, crushing, or rubbing, as in a mill or a mortar, or with the teeth; bray; triturate: as, to grind corn.; grind To produce by grinding, or by action comparable to that of grinding: as, to grind flour; to grind out a tune on an organ.; grind To wear down, smooth, or sharpen by friction; give a smooth surface, edge, or point to, as by ...