• (n.) A colorless, amorphous substance which is produced by the reduction of fluorescein, and from which the latter may be formed by oxidation.
Flu`o·res'cin noun (Chemistry) A colorless, amorphous substance which is produced by the reduction of fluoresceïn, and from which the latter may be formed by oxidation. 
Type: Term Pronunciation: flōr′-es-in Definitions: 1. Reduced fluorescein, with uses similar to fluorescein.