pestle

(noun) machine consisting of a heavy bar that moves vertically for pounding or crushing ores. Synonyms: stamp.

(noun) a heavy tool of stone or iron (usually with a flat base and a handle) that is used to grind and mix material (as grain or drugs or pigments) against a slab of stone. Synonyms: muller, pounder.

(noun) a club-shaped hand tool for grinding and mixing substances in a mortar.

(verb) grind, mash or pulverize in a mortar. Example: "Pestle the garlic."