Source : Webster's Revised Unabridged Dictionary (1913)

Pack \Pack\, n. [Akin to D. pak, G. pack, Dan. pakke, Sw. packa,
   Icel. pakki, Gael. & Ir. pac, Arm. pak. Cf. {Packet}.]
   1. A bundle made up and prepared to be carried; especially, a
      bundle to be carried on the back; a load for an animal; a
      bale, as of goods. --Piers Plowman.

   2. [Cf. {Peck}, n.] A number or quantity equal to the
      contents of a pack; hence, a multitude; a burden. ``A pack
      of sorrows.'' ``A pack of blessings.'' --Shak.

   Note: ``In England, by a pack of meal is meant 280 lbs.; of
         wool, 240 lbs.'' --McElrath.

   3. A number or quantity of connected or similar things; as:
      (a) A full set of playing cards; also, the assortment used
          in a particular game; as, a euchre pack.
      (b) A number of hounds or dogs, hunting or kept together.
      (c) A number of persons associated or leagued in a bad
          design or practice; a gang; as, a pack of thieves or
          knaves.
      (d) A shook of cask staves.
      (e) A bundle of sheet-iron plates for rolling
          simultaneously.

   4. A large area of floating pieces of ice driven together
      more or less closely. --Kane.

   5. An envelope, or wrapping, of sheets used in hydropathic
      practice, called dry pack, wet pack, cold pack, etc.,
      according to the method of treatment.

   6. [Prob. the same word; but cf. AS. p?can to deceive.] A
      loose, lewd, or worthless person. See {Baggage}. [Obs.]
      --Skelton.

   {Pack animal}, an animal, as a horse, mule, etc., employed in
      carrying packs.

   {Pack cloth}, a coarse cloth, often duck, used in covering
      packs or bales.

   {Pack horse}. See {Pack animal} (above).

   {Pack ice}. See def. 4, above.

   {Pack moth} (Zo["o]l.), a small moth ({Anacampsis
      sarcitella}) which, in the larval state, is very
      destructive to wool and woolen fabrics.

   {Pack needle}, a needle for sewing with pack thread. --Piers
      Plowman.

   {Pack saddle}, a saddle made for supporting the load on a
      pack animal. --Shak.

   {Pack staff}, a staff for supporting a pack; a peddler's
      staff.

   {Pack thread}, strong thread or small twine used for tying
      packs or parcels.

   {Pack train} (Mil.), a troop of pack animals.

Source : WordNet®

pack animal
     n : an animal such as a mule or burro or horse used to carry
         loads [syn: {sumpter}]