n. One who or that which purifies or cleanses; a cleanser; a refiner; specifically, a purificator.n. In milling, an apparatus for separating branscales and flour from grits or middlings.n. In the manufacture of coal-gas, the tank or chamber in which the gas is exposed to the action of slaked lime, or to a mixture of this with the oxyhydroxid of iron, in order to remove objectionable constituents, especially carbon dioxid and sulphureted hydrogen.n. A device for cleansing water from injurious or undesirable impurities.