Source : Webster's Revised Unabridged Dictionary (1913)

Uranin \U"ra*nin\, n. (Chem.)
   An alkaline salt of fluorescein, obtained as a brownish red
   substance, which is used as a dye; -- so called from the
   peculiar yellowish green fluorescence (resembling that of
   uranium glass) of its solutions. See {Fluorescein}.