Grinder

Webster's Dictionary of the English Language

·noun One who, or that which, grinds.

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

III. Grinder ·noun 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.