Pronunciation: (les'u-thin), [key]
1. Biochem.any of a group of phospholipids, occurring in animal and plant tissues and egg yolk, composed of units of choline, phosphoric acid, fatty acids, and glycerol.
2. a commercial form of this substance, obtained chiefly from soybeans, corn, and egg yolk, used in foods, cosmetics, and inks.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.