noun Chemistry, Biochemistry.
- part of the folic acid molecule, a white or yellowish, crystalline, slightly water-soluble solid, C7H7NO2, the para isomer of aminobenzoic acid: used chiefly in the manufacture of dyes and pharmaceuticals and in sunscreens to protect against ultraviolet light. Abbreviation: PABA
- biochem an acid present in yeast and liver: used in the manufacture of dyes and pharmaceuticals. Formula: C 6 H 4 (NH 2)COOH
- See PABA.