Sulfide, compound of sulfur and another element or elements. The element—made up of atoms that are alike and cannot be changed chemically—may be a metal, such as silver or gold, or a gas, such as oxygen or hydrogen. Sulfides have various industrial uses. When sulfur burns, it produces a poisonous gas. A mixture of carbon and sulfur is used as an insecticide. In small doses, it is used as an anesthetic. Some sulfides are used to create color in paints.