• (n.) A colorless, crystalline hydrocarbon, C20H14, obtained from naphthylene, and consisting of a doubled naphthylene radical.
di·naph'thyl noun [ Prefix di- + naphthyl ene.] (Chemistry) A colorless, crystalline hydrocarbon, C 20 H 14 , obtained from naphthylene, and consisting of a doubled naphthylene radical.