The Collaborative International Dictionary
Dioxindol
Dioxindol \Di`ox*in"dol\, n. [Pref. di- + oxygen + indol.] (Chem.) A white, crystalline, nitrogenous substance obtained by the reduction of isatin. It is a member of the indol series; -- hence its name.
Wiktionary
dioxindol
n. (context organic compound English) An indol obtained by the reduction of isatin.