Source : Webster's Revised Unabridged Dictionary (1913)

Balsam \Bal"sam\, n. [L. balsamum the balsam tree or its resin,
   Gr. ?. See {Balm}, n.]
   1. A resin containing more or less of an essential or
      volatile oil.

   Note: The balsams are aromatic resinous substances, flowing
         spontaneously or by incision from certain plants. A
         great variety of substances pass under this name, but
         the term is now usually restricted to resins which, in
         addition to a volatile oil, contain benzoic and
         cinnamic acid. Among the true balsams are the balm of
         Gilead, and the balsams of copaiba, Peru, and Tolu.
         There are also many pharmaceutical preparations and
         resinous substances, possessed of a balsamic smell, to
         which the name balsam has been given.

   2. (Bot.)
      (a) A species of tree ({Abies balsamea}).
      (b) An annual garden plant ({Impatiens balsamina}) with
          beautiful flowers; balsamine.

   3. Anything that heals, soothes, or restores.

            Was not the people's blessing a balsam to thy blood?
                                                  --Tennyson.

   {Balsam apple} (Bot.), an East Indian plant ({Momordica
      balsamina}), of the gourd family, with red or
      orange-yellow cucumber-shaped fruit of the size of a
      walnut, used as a vulnerary, and in liniments and
      poultices.

   {Balsam fir} (Bot.), the American coniferous tree, {Abies
      balsamea}, from which the useful Canada balsam is derived.
      

   {Balsam of copaiba}. See {Copaiba}.

   {Balsam of Mecca}, balm of Gilead.

   {Balsam of Peru}, a reddish brown, syrupy balsam, obtained
      from a Central American tree ({Myroxylon Pereir[ae]} and
      used as a stomachic and expectorant, and in the treatment
      of ulcers, etc. It was long supposed to be a product of
      Peru.

   {Balsam of Tolu}, a reddish or yellowish brown semisolid or
      solid balsam, obtained from a South American tree
      ({Myroxylon toluiferum}). It is highly fragrant, and is
      used as a stomachic and expectorant.

   {Balsam tree}, any tree from which balsam is obtained, esp.
      the {Abies balsamea}.

   {Canada balsam}, {Balsam of fir}, Canada turpentine, a
      yellowish, viscid liquid, which, by time and exposure,
      becomes a transparent solid mass. It is obtained from the
      balm of Gilead (or balsam) fir ({Abies balsamea}) by
      breaking the vesicles upon the trunk and branches. See
      {Balm}.

Source : WordNet®

balsam of Peru
     n : dark brown syrupy balsam from the Peruvian balsam tree used
         especially in dressing wounds and treating certain skin
         diseases