APA Dictionary of Psychology

n. a steroid derivative abundant in animal tissues, found especially in foods rich in animal fats. Cholesterol is a constituent of plasma membranes, the precursor of other steroids (e.g., the sex hormones), and a component of plasma lipoproteins, especially low-density lipoproteins (LDLs), which are believed to play an important role in forming atherosclerotic plaques (see atherosclerosis).