- noun a fatty substance found in fats and oils. It is produced by the liver and forms an essential part of cells.
- A complex alcohol (sterol) found in most body tissues and many foods. It is a high-molecular-weight alcohol normally synthesized by the liver, a constituent of cell membranes and a precursor of steroid hormones. There is a total of about 140 g in the body most of which is synthesized in the body. There is no evidence that dietary cholesterol influences the amount of body cholesterol. The concentration in blood is thought to be an indicator of other problems predisposing to heart and vascular system disease.