Source : Webster's Revised Unabridged Dictionary (1913)

Switch \Switch\, n. (Elec.)
   A device for shifting an electric current to another circuit,
   or for making and breaking a circuit.

Switch \Switch\, v. t. [imp. & p. p. {Switched}; p. pr. & vb. n.
   {Switching}.]
   1. To strike with a switch or small flexible rod; to whip.
      --Chapman.

   2. To swing or whisk; as, to switch a cane.

   3. To trim, as, a hedge. [Prov. Eng.] --Halliwell.

   4. To turn from one railway track to another; to transfer by
      a switch; -- generally with off, from, etc.; as, to switch
      off a train; to switch a car from one track to another.

   5. (Eccl.) To shift to another circuit.

Switch \Switch\, n. [Cf. OD. swick a scourage, a whip. Cf.
   {Swink}, {Swing}.]
   1. A small, flexible twig or rod.

            Mauritania, on the fifth medal, leads a horse with
            something like a thread; in her other hand she holds
            a switch.                             --Addison.

   2. (Railways) A movable part of a rail; or of opposite rails,
      for transferring cars from one track to another.

   3. A separate mass or trees of hair, or of some substance (at
      jute) made to resemble hair, worn on the head by women.

   4. (Elec.) A mechanical device for shifting an electric
      current to another circuit.

   {Safety switch} (Railways), a form of switch contrived to
      prevent or lessen the danger of derailment of trains.

   {Switch back} (Railways), an arrangement of tracks whereby
      elevations otherwise insurmountable are passed. The track
      ascends by a series of zigzags, the engine running
      alternately forward and back, until the summit is reached.
      

   {Switch board} (Elec.), a collection of switches in one piece
      of apparatus, so arranged that a number of circuits may be
      connected or combined in any desired manner.

Switch \Switch\, v. i.
   To walk with a jerk. [Prov. Eng.]

Source : WordNet®

switch
     n 1: control consisting of a mechanical or electrical or
          electronic device for making or breaking or changing the
          connections in a circuit [syn: {electric switch}, {electrical
          switch}]
     2: an event in which one thing is substituted for another; "the
        replacement of lost blood by a transfusion of donor blood"
        [syn: {substitution}, {permutation}, {transposition}, {replacement}]
     3: hairpiece consisting of a tress of false hair; used by women
        to give shape to a coiffure
     4: railroad track having two movable rails and necessary
        connections; used to turn a train from one track to
        another or to store rolling stock
     5: a flexible implement used as an instrument of punishment
     6: a basketball maneuver; two defensive players shift
        assignments so that each guards the player usually guarded
        by the other
     7: the act of changing one thing or position for another; "his
        switch on abortion cost him the election" [syn: {switching},
         {shift}]

switch
     v 1: change over, change around, or switch over [syn: {switch
          over}, {exchange}]
     2: exchange or give (something) in exchange for [syn: {trade},
        {swap}, {swop}]
     3: lay aside, abandon, or leave for another; "switch to a
        different brand of beer"; "She switched psychiatrists";
        "The car changed lanes" [syn: {shift}, {change}]
     4: make a shift in or exchange of; "First Joe led; then we
        switched" [syn: {change over}, {shift}]
     5: cause to go on or to be engaged or set in operation; "switch
        on the light"; "throw the lever" [syn: {throw}, {flip}]
     6: flog with or as if with a flexible rod
     7: reverse (a direction, attitude, or course of action) [syn: {interchange},
         {tack}, {alternate}, {flip}, {flip-flop}]

Source : Free On-Line Dictionary of Computing

switch
     
        1.  {switch statement}.
     
        2.  {command line option}.
     
        3.  {packet switch}, {circuit switch}.
     
        (1999-01-14)