tannic acid
(TA-nik A-sid)
A type of chemical found in plants and in certain foods, such as fruits, vegetables, nuts, wine, and tea. Tannic acid has antioxidant properties and may promote good health. It is being studied in the prevention of cancer, heart disease, and other diseases. It is also used in certain medicines, fabrics, leather, and ink. Tannic acid is a type of polyphenol. Also called tannin.