What does cholesterol mean?
Cholesterol is a soft, waxy substance classified chemically as a sterol — a type of lipid or fat. Far from being merely a dietary villain, it is indispensable to life: every animal cell relies on it to build flexible membranes, and the body uses it as raw material for making bile acids, vitamin D, and hormones such as oestrogen and testosterone. Most circulating cholesterol is manufactured by the liver rather than absorbed from food. In everyday usage, however, the word carries strong health connotations: when people speak of 'high cholesterol', they usually mean elevated levels of low-density lipoprotein (LDL) in the blood, which can deposit in artery walls and raise the risk of heart attack and stroke. Because of this, cholesterol appears constantly in medical advice, nutrition labelling, and advertising for foods and drugs, giving the word a familiar but ambivalent place in public language about diet and wellbeing.
nounA waxy, fat-like substance (a sterol) found in the cells and bloodstream of animals, essential for building cell membranes and producing hormones and vitamin D; high levels of certain forms in the blood are associated with an increased risk of heart disease.
- A sterol lipid present in animal cell membranes and blood plasma, vital for membrane structure and the synthesis of hormones, vitamin D, and bile acids.
- The measured level of this substance in the blood, especially as a clinical indicator of cardiovascular risk (e.g. 'high' or 'good' cholesterol).
"Her doctor advised her to cut back on saturated fat after a blood test showed high cholesterol."
"Eggs were long blamed for raising cholesterol, though dietary cholesterol has less impact on blood levels than once thought."
"Statins work by reducing the amount of cholesterol the liver produces."
Cholesterol is a mass noun and does not take a plural form; quantities are expressed through phrases such as 'cholesterol levels'.
"Both patients had dangerously high cholesterol."
Your body makes all the cholesterol it needs — most of it in your liver — so the cholesterol in your breakfast plate is largely optional.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of cholesterol
The word cholesterol was coined in the nineteenth century from Greek roots: 'chole', meaning bile, and 'stereos', meaning solid, reflecting its discovery as a solid substance found in gallstones. The '-ol' ending was added later to signal that the compound is an alcohol in chemical terms. Its formation places it alongside other scientific terms built from Greek elements, such as cholic acid and the steroid family of compounds derived from the same sterol framework.
How cholesterol is actually used
Cholesterol is an uncountable noun used almost exclusively in scientific and health contexts. In everyday speech it often carries negative connotations because of its link to heart disease, though medically it refers to a substance that is both necessary and potentially harmful depending on the type and amount. It takes no plural form.
Easily confused with cholesterol
Choline is a water-soluble nutrient similar to a B vitamin, whereas cholesterol is a waxy lipid; the two share only a superficial spelling resemblance.