ldl(n = noun.substance) beta-lipoprotein, low-density lipoprotein - a lipoprotein that transports cholesterol in the blood; composed of moderate amount of protein and a large amount of cholesterol; high levels are thought to be associated with increased risk of coronary heart disease and atherosclerosis;
Low-density lipoprotein, a lipoprotein that transports cholesterol in the blood; high levels are thought to be associated with increased risk of coronary heart disease and atherosclerosis; sometimes called informally bad cholesterol. [WordNet 1.5]