1. (n.) Same as Id.

2. (n.) A suffix used to denote: (a) The nonmetallic, or negative, element or radical in a binary compound; as, oxide, sulphide, chloride. (b) A compound which is an anhydride; as, glycolide, phthalide. (c) Any one of a series of derivatives; as, indogenide, glucoside, etc.