·noun A solid crystallizable fat, found abundantly in animals and in vegetables. It occurs mixed with stearin and olein in the fat of animal tissues, with olein and butyrin in butter, with olein in olive oil, ·etc. Chemically, it is a glyceride of palmitic acid, three molecules of palmitic acid being united to one molecule of glyceryl, and hence it is technically called tripalmitin, or glyceryl tripalmitate.