turn on phr v [T] 1 [ turn sth ↔ on] to make a machine, light etc start working, or make water, electricity etc start flowing 打开〔机器、电灯等〕; 打开〔水、电等〕的开关: Could you turn on the TV? 你能打开电视机吗？ 2 [ turn on sb] to suddenly attack or criticize someone 突然袭击［指责］〔某人〕: The dog turned on him and bit him. 那只狗突然向他扑来咬了他。