Source : Webster's Revised Unabridged Dictionary (1913)

Caoutchouc \Caout"chouc\, n. [F. caoutchouc, from the South
   American name.]
   A tenacious, elastic, gummy substance obtained from the milky
   sap of several plants of tropical South America (esp. the
   euphorbiaceous tree {Siphonia elastica} or {Hevea
   caoutchouc}), Asia, and Africa. Being impermeable to liquids
   and gases, and not readly affected by exposure to air, acids,
   and alkalies, it is used, especially when vulcanized, for
   many purposes in the arts and in manufactures. Also called
   {India rubber} (because it was first brought from India, and
   was formerly used chiefly for erasing pencil marks) and {gum
   elastic}. See {Vulcanization}.

   {Mineral caoutchouc}. See under {Mineral}.