1. Any of various hand-driven or electric devices used to reduce food to small particles of varying degrees. Coffee grinders are electric and usually have an exposed, disk-style blade inside the unit's container. The grind can be adjusted from fine to coarse. Some nuts and spices can also be ground in a coffee grinder. Meat grinders can be either manual (operated by a hand crank) or electric; the housing can be made of cast iron or tough plastic. Hand-operated meat grinders are attached to a countertop by a clamp-and-screw mechanism, whereas electric models are freestanding. They both work on the same principle, by forcing chunks of meat through a rotating blade, then through a perforated cutting disk. See also nut mill. 2. In some regions, "grinder" also refers to a huge sandwich; see hero sandwich.