a yellow, crystalline aromatic carcinogenic hydrocarbon, C 20 H 12 , consisting of five fused benzene rings, produced by incomplete combustion of organic material, as coal, petroleum, or tobacco.
noun a yellow crystalline water-soluble unsaturated ketone manufactured from aniline and used in the production of dyestuffs. Formula: C6H4O2 Also called quinone Systematic name cyclohexadiene-1,4-quinone Historical Examples Coal Raphael Meldola
a colorless or yellowish liquid, C 7 H 5 Cl 3 , used chiefly in the manufacture of dyes. Historical Examples Coal Raphael Meldola