Any of a group of phospholipids found in plants and animals. Lecithin is commonly used in food, such as ice cream, as an emulsifier. Historically most lecithin was prepared from animal tissues, which explains why vegetarians are paranoid about chocolate that does not contain soy lecithin.

Lec"i*thin (?), n. [Gr. the yolk of an egg.] Physiol. Chem.

A complex, nitrogenous phosphorized substance widely distributed through the animal body, and especially conspicuous in the brain and nerve tissue, in yolk of eggs, and in the white blood corpuscles.

© Webster 1913.