(first syllable pronounced either steer or stair) is the saturated fatty acid with an 18 carbon chain and has the IUPAC name octadecanoic acid. It is a waxy solid, and its chemical formula is C18H36O2, orCH3(CH2)16COOH. Its name comes from the Greek word genitiveatos), which means tallow The salts and of stearic acid are called stearates