pestle (Noun) — Machine consisting of a heavy bar that moves vertically for pounding or crushing ores.
pestle (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.
pestle (Noun) — A club-shaped hand tool for grinding and mixing substances in a mortar.
pestle (Verb) — Grind, mash or pulverize in a mortar. ex. "pestle the garlic"