\In"di*can\, n. [See {Indigo}.]
1. (Chem.) A glucoside obtained from woad (indigo plant) and
   other plants, as a yellow or light brown sirup. It has a
   nauseous bitter taste, a decomposes or drying. By the
   action of acids, ferments, etc., it breaks down into sugar
   and indigo. It is the source of natural indigo.

2. (Physiol. Chem.) An indigo-forming substance, found in
   urine, and other animal fluids, and convertible into red
   and blue indigo (urrhodin and uroglaucin). Chemically, it
   is indoxyl sulphate of potash, {C8H6NSO4K}, and is derived
   from the indol formed in the alimentary canal. Called also
   {uroxanthin}.