Gamboge :: Gamboge (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..