stearin, fat that is the triglyceride of stearic acid, CH₃(CH₂)₁₆CO₂H, i.e., the tristearate ester of glycerol. It is a white crystalline solid at ordinary temperatures and is insoluble in water and very slightly soluble in alcohol. It is found (often mixed with palmitin) in many hard fats and oils, e.g., in tallow, suet, butterfat, cottonseed oil, and olive oil. It is used in making soap and candles.