n. One who or that which cleans.n. A special preparation, either saponaceous, ethereal, or both, used for removing grease-spots, ink-stains, etc., from fabrics.n. A device for automatically cleaning scum or floating matter from the surface of water in a boiler and depositing it in a separator or settling-chamber located on top of the boiler. It consists of a skimmer in the boiler, to which is attached a vertical pipe which discharges into the settling-chamber near its top. From a point at the other side of the settling-chamber a return-pipe leads into the boiler, discharging somewhat below the water-level.