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

For decades, they were demonized because of their cholesterol content. — Laura Solla, Vogue, 21 Oct. 2026

These findings helped establish PCSK9 as a drug target and contributed to the development of PCSK9 inhibitors, a new class of cholesterol-lowering medicines now used around the world. — Segun Fatumo, semafor.com, 19 Oct. 2026

So Merck released Lipfendra—a once-daily pill form of an injectable medication that’s been available for years—which helps the body clear more LDL cholesterol by blocking the blood protein PCSK9. — Erica Sweeney, Time, 15 Oct. 2026

With less cholesterol circulating in the blood, arteries can stay more flexible, allowing blood to flow more freely and helping blood pressure to remain low. — Sarah Garone, HEALTH, 15 Oct. 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