lecithin

/ˈlɛs.ə.θɪn/

IPA: /L EH1 S AH0 TH AH0 N/

noun
  1. 1

    The principal phospholipid in animals; it is particularly abundant in egg yolks, and is extracted commercially from soy. It is a major constituent of cell membranes, and is commonly used as a food additive (as an emulsifier).

Source: https://en.wiktionary.org/wiki/lecithin