• (n.) A double benzene and thiophene nucleus, C8H6S, analogous to naphthalene, and like it the base of a large series of derivatives.
Thi`o·naph'thene noun [ Thio phene + naphth al ene .] (Chemistry) A double benzene and thiophene nucleus, C 8 H 6 S, analogous to naphthalene, and like it the base of a large series of derivatives. [ Written also thionaphtene .]