C₆H₄Cl₂ Any of a group of substitution products of benzene and two atoms of chlorine; the three forms are meta-dichlorobenzene, colorless liquid boiling at 172°C, soluble in alcohol and ether, insoluble in water, or ortho-, colorless liquid boiling at 179°C, used as a solvent and chemical intermediate, or para- , volatile white crystals, insoluble in water, soluble in organic solvents, used as a germicide, insecticide, and chemical intermediate.