Source : Webster's Revised Unabridged Dictionary (1913)

Pipe \Pipe\, n. [AS. p[=i]pe, probably fr. L. pipare, pipire, to
   chirp; of imitative origin. Cf. {Peep}, {Pibroch}, {Fife}.]
   1. A wind instrument of music, consisting of a tube or tubes
      of straw, reed, wood, or metal; any tube which produces
      musical sounds; as, a shepherd's pipe; the pipe of an
      organ. ``Tunable as sylvan pipe.'' --Milton.

            Now had he rather hear the tabor and the pipe.
                                                  --Shak.

   2. Any long tube or hollow body of wood, metal, earthenware,
      or the like: especially, one used as a conductor of water,
      steam, gas, etc.

   3. A small bowl with a hollow steam, -- used in smoking
      tobacco, and, sometimes, other substances.

   4. A passageway for the air in speaking and breathing; the
      windpipe, or one of its divisions.

   5. The key or sound of the voice. [R.] --Shak.

   6. The peeping whistle, call, or note of a bird.

            The earliest pipe of half-awakened birds.
                                                  --Tennyson.

   7. pl. The bagpipe; as, the pipes of Lucknow.

   8. (Mining) An elongated body or vein of ore.

   9. A roll formerly used in the English exchequer, otherwise
      called the Great Roll, on which were taken down the
      accounts of debts to the king; -- so called because put
      together like a pipe. --Mozley & W.

   10. (Naut.) A boatswain's whistle, used to call the crew to
       their duties; also, the sound of it.

   11. [Cf. F. pipe, fr. pipe a wind instrument, a tube, fr. L.
       pipare to chirp. See Etymol. above.] A cask usually
       containing two hogsheads, or 126 wine gallons; also, the
       quantity which it contains.

   {Pipe fitter}, one who fits pipes together, or applies pipes,
      as to an engine or a building.

   {Pipe fitting}, a piece, as a coupling, an elbow, a valve,
      etc., used for connecting lengths of pipe or as accessory
      to a pipe.

   {Pipe office}, an ancient office in the Court of Exchequer,
      in which the clerk of the pipe made out leases of crown
      lands, accounts of cheriffs, etc. [Eng.]

   {Pipe tree} (Bot.), the lilac and the mock orange; -- so
      called because their were formerly used to make pipe
      stems; -- called also {pipe privet}.

   {Pipe wrench}, or {Pipetongs}, a jawed tool for gripping a
      pipe, in turning or holding it.

   {To smoke the pipe of peace}, to smoke from the same pipe in
      token of amity or preparatory to making a treaty of peace,
      -- a custom of the American Indians.

Pipe \Pipe\, v. t. [imp. & p. p. {Piped}; p. pr. & vb. n.
   {Piping}.]
   1. To perform, as a tune, by playing on a pipe, flute, fife,
      etc.; to utter in the shrill tone of a pipe.

            A robin . . . was piping a few querulous notes. --W.
                                                  Irving.

   2. (Naut.) To call or direct, as a crew, by the boatswain's
      whistle.

            As fine a ship's company as was ever piped aloft.
                                                  --Marryat.

   3. To furnish or equip with pipes; as, to pipe an engine, or
      a building.

Pipe \Pipe\, v. i.
   1. To play on a pipe, fife, flute, or other tubular wind
      instrument of music.

            We have piped unto you, and ye have not danced.
                                                  --Matt. xi.
                                                  17.

   2. (Naut.) To call, convey orders, etc., by means of signals
      on a pipe or whistle carried by a boatswain.

   3. To emit or have a shrill sound like that of a pipe; to
      whistle. ``Oft in the piping shrouds.'' --Wordsworth.

   4. (Metal.) To become hollow in the process of solodifying;
      -- said of an ingot, as of steel.

Source : WordNet®

pipe
     n 1: a tube with a small bowl at one end; used for smoking
          tobacco [syn: {tobacco pipe}]
     2: a long tube made of metal or plastic that is used to carry
        water or oil or gas etc. [syn: {pipage}, {piping}]
     3: a hollow cylindrical shape [syn: {tube}]
     4: a tubular wind instrument [syn: {tabor pipe}]
     5: the flues and stops on a pipe organ [syn: {organ pipe}, {pipework}]

pipe
     v 1: utter a shrill cry [syn: {shriek}, {shrill}, {pipe up}]
     2: transport by pipeline; "pipe oil, water, and gas into the
        desert"
     3: play on a pipe; "pipe a tune"
     4: trim with piping; "pipe the skirt"

Source : Free On-Line Dictionary of Computing

pipe
     
        1.  One of {Unix}'s buffers which can be
        written to by one {asynchronous} process and read by another,
        with the {kernel} suspending and waking up the sender and
        receiver according to how full the pipe is.  In later versions
        of Unix, rather than using an anonymous kernel-managed
        temporary file to implement a pipe, it can be named and is
        implemented as a local {socket} pair.
     
        2.  "|" {ASCII} character 124.  Used to represent a
        pipe between two processes in a {shell} command line.  E.g.
     
        	grep foo log | more
     
        which feeds the output of grep into the input of more without
        requiring a named temporary file and without waiting for the
        first process to finish.
     
        3.  A connection to a {network}.
     
        See also {light pipe}.
     
        (1996-09-24)