Definitions of switch:

• noun:   the act of changing one thing or position for another

  Example: "His switch on abortion cost him the election"

• noun:   a basketball maneuver; two defensive players shift assignments so that each guards the player usually guarded by the other
• noun:   a flexible implement used as an instrument of punishment
• noun:   control consisting of a mechanical or electrical or electronic device for making or breaking or changing the connections in a circuit
• noun:   railroad track having two movable rails and necessary connections; used to turn a train from one track to another or to store rolling stock
• noun:   hairpiece consisting of a tress of false hair; used by women to give shape to a coiffure
• noun:   an event in which one thing is substituted for another
• verb:   make a shift in or exchange of

  Example: "Then we switched"

• verb:   lay aside, abandon, or leave for another

  Example: "Switch to a different brand of beer"

• verb:   flog with or as if with a flexible rod
• verb:   change over, change around, or switch over
• verb:   reverse (a direction, attitude, or course of action)
• verb:   cause to go on or to be engaged or set in operation

  Example: "Switch on the light"

• verb:   exchange or give (something) in exchange for