lipid

American  

[lip-id, lahy-pid] / ˈlɪp ɪd, ˈlaɪ pɪd /

Also lipide

noun

Biochemistry.

1. any of a group of organic compounds that are greasy to the touch, insoluble in water, and soluble in alcohol and ether: lipids comprise the fats and other esters with analogous properties and constitute, with proteins and carbohydrates, the chief structural components of living cells.

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lipid British  

/ ˈlɪpɪd, ˈlaɪpɪd /

noun

1. Former name: lipoid.  biochem any of a large group of organic compounds that are esters of fatty acids ( simple lipids , such as fats and waxes) or closely related substances ( compound lipids , such as phospholipids): usually insoluble in water but soluble in alcohol and other organic solvents. They are important structural materials in living organisms

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lipid Scientific  

/ lĭp′ĭd /

1. Any of a large group of organic compounds that are oily to the touch and insoluble in water. Lipids include fatty acids, oils, waxes, sterols, and triglycerides. They are a source of stored energy and are a component of cell membranes.

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Etymology

Origin of lipid

First recorded in 1920–25; lip- + -id ³

Explanation

A lipid is a waxy or oily organic molecule that is insoluble in water. Certain vitamins, like A, D, E, and K, are lipids. Lipids are sometimes described as fat-soluble, rather than water-soluble. A more precise way to think of them is "soluble in organic solvents." The same way a dollop of oil floats on a bowl of water, or a greasy pan only gets clean once you've added dish soap to the water, a lipid keeps itself separate from water. This gives it the ability to store energy and provide insulation. Lipid is derived from the Greek lipos, "fat or grease."

Example Sentences

These receptors are important for maintaining healthy communication between neurons and supporting lipid metabolism.

From Science Daily • May 20, 2026

On lipid droplets, HSL acts as an enzyme that helps release stored fat during fasting or exercise.

From Science Daily • May 8, 2026

The companies had accused Moderna of using their patented lipid nanoparticle technology—the delivery system featured in Moderna’s Spikevax Covid-19 vaccine—without permission.

From Barron's • May 1, 2026

Inside these cells, fat is packed into structures called lipid droplets, which act as fuel reserves the body can draw on when needed, such as during fasting between meals.

From Science Daily • Apr. 30, 2026

Before Citra left home, Mrs. Yeltner had reset her lipid point to svelte.

From "Scythe" by Neal Shusterman