The Collaborative International Dictionary
Fluorescin
Fluorescin \Flu`o*res"cin\, n. (Chem.) A colorless, amorphous substance which is produced by the reduction of fluoresce["i]n, and from which the latter may be formed by oxidation.
Wiktionary
fluorescin
n. (context organic compound English) A colourless amorphous substance produced by the reduction of fluorescein, and from which the latter may be formed by oxidation.