One of a group of naturally occurring compounds that are soluble in solvents such as chloroform or alcohol, but insoluble in water. Lipids are important dietary constituents, not only because of their high energy value but also because certain vitamins and essential fatty acids are associated with them. The group includes fats, steroids, phospholipids and glycolipids.

Unit 2,

Reference: Oxford Concise Colour Medical Dictionary (7th Edition, Kindle Edition) Oxford University Press 2020 ISBN-13: 978-0198836629, p1788