Switch

1. A device used to break or open an electric circuit or to divert current from one conductor to another. He turned on the light using the wall switch.
2. A slender flexible rod, or twig, especially one used for whipping. Mom would use a switch on our backside when we misbehaved.
3. To exchange. He asked her brother to switch seats with her.
4. To shift, transfer, or divert. He switched the conversation to another subject.