Source : Webster's Revised Unabridged Dictionary (1913)

Gamboge \Gam*boge"\, n.
   A concrete juice, or gum resin, produced by several species
   of trees in Siam, Ceylon, and Malabar. It is brought in
   masses, or cylindrical rolls, from Cambodia, or Cambogia, --
   whence its name. The best kind is of a dense, compact
   texture, and of a beatiful reddish yellow. Taking internally,
   it is a strong and harsh cathartic and emetic. [Written also
   {camboge}.]

   Note: There are several kinds of gamboge, but all are derived
         from species of {Garcinia}, a genus of trees of the
         order {Guttifer[ae]}. The best Siam gamboge is thought
         to come from {Garcinia Hanburii}. Ceylon gamboge is
         from {G. Morella}. {G. pictoria}, of Western India,
         yields {gamboge}, and also a kind of oil called
         {gamboge butter}.

Source : WordNet®

gamboge
     n 1: a gum resin used as a yellow pigment and a purgative
     2: a strong yellow color [syn: {lemon}, {lemon yellow}, {maize}]