cholesterol

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A white crystalline substance, C₂₇H₄₅OH, found in animal tissues and various foods, that is normally synthesized by the liver and is important as a constituent of cell membranes and a precursor to steroid hormones. Cholesterol is transported through the bloodstream as different types of lipoproteins, two of which (HDL cholesterol and LDL cholesterol) are routinely measured in blood tests.
• noun HDL cholesterol.
• noun LDL cholesterol.

from The Century Dictionary.

• noun Same as cholesterin. The termination -ol is used to indicate that chemically the substance belongs to the class of alcohols.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun biochemistry A sterol lipid synthesized by the liver and transported in the bloodstream to the membranes of all animal cells; it plays a central role in many biochemical processes and, as a lipoprotein that coats the walls of blood vessels, is associated with cardiovascular disease.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun an animal sterol that is normally synthesized by the liver; the most abundant steroid in animal tissues