1. [n]  the act of changing one thing or position for another; "his switch on abortion cost him the election"
2. [n]  a basketball maneuver; two defensive players shift assignments so that each guards the player usually guarded by the other
3. [n]  a flexible implement used as an instrument of punishment
4. [n]  control consisting of a mechanical or electrical or electronic device for making or breaking or changing the connections in a circuit
5. [n]  railroad track having two movable rails and necessary connections; used to turn a train from one track to another or to store rolling stock
6. [n]  hairpiece consisting of a tress of false hair; used by women to give shape to a coiffure
7. [n]  an event in which one thing is substituted for another; "the replacement of lost blood by a transfusion of donor blood"
8. [v]  reverse, as of direction, attitude, or course of action
9. [v]  change over, change around, or switch over
10. [v]  make a shift in or exchange of; "First Joe led; then we switched"
11. [v]  lay aside, abandon, or leave for another; "switch to a different brand of beer"; "She switched psychiatrists"; "The car changed lanes"
12. [v]  flog with or as if with a flexible rod
13. [v]  cause to go on or t be engaged; set in operation; "switch on the light"; "throw the lever"
14. [v]  exchange or give (something) in exchange for

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

2. \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 grass}. (Bot.) See under {Grass}.
   
   

3. \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.
   
   

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

1. switch statement.

2. command line option.

3. packet switch, circuit switch.