acetylsalicylic acid

(noun) the acetylated derivative of salicylic acid; used as an analgesic anti-inflammatory drug (trade names Bayer, Empirin, and St. Joseph) usually taken in tablet form; used as an antipyretic; slows clotting of the blood by poisoning platelets. Synonyms: aspirin, acetylsalicylic acid, Bayer, Empirin, St. Joseph.