(chemistry) Any polyunsaturated fatty acid

(chemistry, dated) The poisonous glucoside saponin.

(organic chemistry, pharmacology) An organic unsaturated fatty acid derived from natural castor oil (ricinoleic acid). It has fungicidal properties and is used in the treatment of skin disorders, nail fungus etc.

(chemistry) A polymer of methacrylic acid

(inorganic chemistry) Any of several ill-defined polymers of orthophosphoric acid; they are viscous, hygroscopic liquids

(inorganic chemistry) Ordinary phosphoric acid, H₃PO₄

(chemistry) Any acid of the form H₂SₙO₆ having a chain of sulfur atoms

(chemistry) Any organic compound having multiple carboxylic acid functional groups

(chemistry) Any acid formed from a binary compound of hydrogen and a halogen

(obsolete, chemistry) Any of a series of condensation products of silicic acid