Lead oxide, also known as lead (II) oxide or plumbous oxide, is an inorganic compound with the chemical formula PbO. It is a grayish black powder that is insoluble in water and has a sweetish taste. Lead oxide is commonly used in the manufacturing of batteries, ceramics, glass, and paints. It is also used as a corrosion inhibitor and as a pigment in the cosmetic industry. Synonyms for lead oxide include lead monoxide, litharge, massicot, and plumbic oxide. Each of these synonyms describes the same chemical compound, but may be used in different contexts or industries.