Source : Webster's Revised Unabridged Dictionary (1913)

Resin \Res"in\ (r?z"?n), n. [F. r['e]sine, L. resina; cf. Gr.
   "rhti`nh Cf. {Rosin}.]
   Any one of a class of yellowish brown solid inflammable
   substances, of vegetable origin, which are nonconductors of
   electricity, have a vitreous fracture, and are soluble in
   ether, alcohol, and essential oils, but not in water;
   specif., pine resin (see {Rosin}).

   Note: Resins exude from trees in combination with essential
         oils, gums, etc., and in a liquid or semiliquid state.
         They are composed of carbon, hydrogen, and oxygen, and
         are supposed to be formed by the oxidation of the
         essential oils. Copal, mastic, quaiacum, and colophony
         or pine resin, are some of them. When mixed with gum,
         they form the gum resins, like asafetida and gamboge;
         mixed with essential oils, they frorm balsams, or
         oleoresins.

   {Highgate resin} (Min.), a fossil resin resembling copal,
      occuring in blue clay at Highgate, near London.

   {Resin bush} (Bot.), a low composite shrub ({Euryops
      speciosissimus}) of South Africa, having smooth pinnately
      parted leaves and abounding in resin.

Source : WordNet®

resin
     n : any of a class of solid or semisolid viscous substances
         obtained either as exudations from certain plants or
         prepared by polymerization of simple molecules [syn: {rosin}]