Source : Webster's Revised Unabridged Dictionary (1913)

Indican \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}.