​STEARIC ACID, n-Octodecylic acid CH₃(CH₂)₁₆CO ₂H, an organic acid found as its glyceride stearin, mixed with palrnitin and olein, in most tallows (hence its name, from Gr. στέαρ, tallow). The so-called “stearin” of candles is a mixture of stearic and palmitic acids (see Candle).