ˌindəˈfēnə̇n, ə̇nˈdäfənə̇n noun
Etymology: International Scientific Vocabulary ind- (II) + phene + -in; from a belief that it was a derivative of benzene; originally formed in German
: a blue crystalline compound C 24 H 14 N 2 O 2 S 2 formed by reaction of thiophene with isatin and sulfuric acid and used as a color test for the presence of thiophene in technical benzene