/les"euh thin/ , n.
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.
[ 1860-65; lékith ( os ) egg yolk + -IN 2 ]