a colorless crystalline acid with a fruity taste; used in making polyester resins
an unsaturated organic dicarboxylic acid, HOOCCH=CHCOOH, the geometric isomer of maleic acid from which it may be prepared by heating; it is found in many plants, including fungi and mosses, and is essential in the chemistry of respiration; it has a number of industrial applications, and its esters, the fumarates, are used in the treatment of psoriasis