Grinder

One who, or that which, grinds.

One of the double teeth, used to grind or masticate the food; a molar.

The restless flycatcher (Seisura inquieta) of Australia; -- called also restless thrush and volatile thrush. It makes a noise like a scissors grinder, to which the name alludes.

a machine tool that polishes metal

machinery that processes materials by grinding or crushing