Thiophene

noun

1. A colorless liquid, C4H4S, containing an aromatic ring composed of a sulfur atom and four carbon atoms, used as a solvent and in organic synthesis.
2. A compound, C4H4S, related to benzene, and forming a large number of derivatives analogous to those of benzin.
3. A sulphur hydrocarbon, C4H4S, analogous to furfuran and benzene, and acting as the base of a large number of substances which closely resemble the corresponding aromatic derivatives.
4. Any of a class of aromatic heterocyclic compounds containing a ring of four carbon atoms and an sulphur atom; especially the simplest one, C4H4S.