v. cause to operate by flipping a switch; "switch on the light"; "turn on the stereo"

v. change to the contrary; "The trend was reversed"; "the tides turned against him"; "public opinion turned when it was revealed that the president had an affair with a White House intern"

v. cause to stop operating by disengaging a switch; "Turn off the stereo, please"; "cut the engine"; "turn out the lights"