(organic chemistry) A crystalline unsaturated hydroxy fatty acid C₁₈H₃₄O₃ that yields esters important as plasticizers and whose glyceride (ricinolein) is the main component of castor oil.

(organic chemistry, biochemistry) A yellowish organic keto acid, 2-oxopropanoic acid, which occurs as an intermediate in many metabolic processes, especially glycolysis.

(organic chemistry) an aliphatic dicarboxylic acid, (CH₂)₈(COOH)₂, originally prepared from tallow; it is used in the manufacture of resins, plasticizers and polyester rubbers

(chemistry) a weak acid, either of two hydrated forms of titanium dioxide, H₂TiO₃ or H₄TiO₄; used as a mordant

(chemistry) dihydroxycinnamic acid, obtained from certain umbelliferous plants

(chemistry) Any of a class of aliphatic carboxylic acids, of general formula CₙH₂ₙ₊₁COOH, that occur combined with glycerol as animal or vegetable oils and fats. Only those with an even number of carbon atoms are normally found in natural fats.

(organic chemistry) 2-hydroxy-propanoic acid (CH₃.CHOH.CO₂H), a syrupy liquid, soluble in water; found in milk, wine and many fruits; used as a food additive and in many industrial applications.

(organic chemistry) An unsaturated organic acid, CH₃-CH=C(CH₃-COOH), found in angelica and having pharmacological uses; the trans- form is tiglic acid.

(chemistry) a weak, unstable acid, HOCl, known only in solution; it is made by the action of chlorine on water and, along with its salts, the hypochlorites, is used as a household bleach

(organic chemistry) A dicarboxylic acid, HOOC-(CHOH)₄-COOH, produced by the oxidation of the milk sugar galactose, used as a test for the presence of galactose and/or lactose.