cholesterol

noun

cho·​les·​ter·​ol kə-ˈle-stə-ˌrȯl 

-ˌrōl

: a waxy, fat-like substance C₂₇H₄₆O that is found in the cells, tissues, and body fluids of humans and animals and that serves as a component of cell membranes and functions as a precursor of vitamin D and steroid hormones (such as cortisol and estrogen)

Note: Cholesterol is produced primarily in the liver and is also derived from dietary sources (such as meat, eggs, and dairy products). It is carried in the bloodstream in the form of lipoproteins, and as a constituent of LDL it may contribute to arterial plaque formation leading to atherosclerosis.

The liver uses cholesterol to produce bile acids, which emulsify fats in the small intestine so they can be more readily absorbed and digested.

—Deane Morrison

Doctors use statins to treat high cholesterol in patients whose condition has not responded to a treatment of dietary changes.

—Joseph Gerstein

In many cases, the flow of oxygen-bearing blood is hindered by a buildup of cholesterol in the coronary arteries …

—Michael Waldholz et al.

Despite being much maligned in the popular press, cholesterol plays a crucial role in organizing cell membranes and controlling their physical properties.

—Amanda Yarnell

see also bad cholesterol, good cholesterol

Examples of cholesterol in a Sentence

Did your doctor check your cholesterol?

Recent Examples on the Web

The condition is often associated with elevated triglycerides and reduced HDL cholesterol, making the ratio a useful surrogate measure of underlying metabolic dysfunction. —Samantha Agate, Sacbee.com, 4 June 2026

The bacteria also competes against viruses for key molecules like cholesterol in the mosquito. —Janet Loehrke, USA Today, 4 June 2026

The triglyceride-to-HDL cholesterol (TG/HDL-C) ratio is a simple, widely available screening marker that flags people who may have insulin resistance. —Samantha Agate, Charlotte Observer, 3 June 2026

Pectins help keep your low-density lipoprotein (LDL) cholesterol in check. —Lauren O'Connor, Health, 2 June 2026

Word History

Etymology

International Scientific Vocabulary, from chol- + Greek stereos solid

First Known Use

1894, in the meaning defined above

Phrases Containing cholesterol

• bad cholesterol
• cholesterol level
• good cholesterol
• high cholesterol

Rhymes for cholesterol

• autosomal
• ergosterol
• lysosomal
• microsomal
• mycorrhizal
• neanderthal
• resorcinol
• ribosomal
• salbutamol
• aerosol
• alcohol
• arbitral

Kids Definition

cholesterol

noun

cho·​les·​ter·​ol kə-ˈles-tə-ˌrōl 

-ˌrȯl

: a waxy substance that is present in animal cells and tissues, is important in bodily processes, and may be related to the abnormal thickening and hardening of arteries when too much is present

Medical Definition

cholesterol

noun

cho·​les·​ter·​ol kə-ˈles-tə-ˌrōl, -ˌrȯl 

: a waxy, fat-like steroid alcohol C₂₇H₄₆O that is found in the cells, tissues, and body fluids of humans and animals, serves as a component of cell membranes and functions as a precursor of vitamin D and steroid hormones, and as a constituent of LDL may contribute to arterial plaque formation leading to atherosclerosis

Note: Cholesterol is produced primarily in the liver and is also derived from dietary sources (such as meat, eggs, and dairy products). It is carried in the bloodstream in the form of lipoproteins.

Cholesterol is a lipid present in the cell membrane and subcellular organelles of tissues throughout the body. … In addition, cholesterol serves as the building block for all steroid hormones including cortisol, aldosterone, estrogen, and testosterone.

—Sarah de Ferranti and David S. Ludwig, The New England Journal of Medicine

… the drug reduces the production of cholesterol in the liver, decreasing the amount of artery-clogging cholesterol circulating in the bloodstream.

—Newsweek