lecithin

lec·i·thin   (lěs'ə-thĭn)    n.  Any of a group of phospholipids found in egg yolks and the plasma membrane of plant and animal cells, used as an emulsifier in a wide range of commercial products, including foods, cosmetics, paints, and plastics. Also called phosphatidylcholine. [French lécithine : Greek lekithos, egg yolk + French -ine, -in.]

lecithin 

Main Entry: lec·i·thin
Pronunciation: 'les-&-th&n
Function: noun
: any of several waxy hygroscopic phospholipids in which phosphatidicacid has formed an ester with choline and which are widely distributed in animals and plants, form colloidal solutions in water, and have emulsifying, wetting, and antioxidant properties; also : a mixture of or a substance rich in lecithins called also phosphatidylcholine

lecithin lec·i·thin (lěs'ə-thĭn)
n.
Any of a group of phospholipids that on hydrolysis yield two fatty acid molecules and a molecule each of glycerophosphoric acid and choline. They are found in nervous tissue, especially myelin sheaths and egg yolk, and in the plasma membrane of plant and animal cells.