to cut; to cut through; to sever (connections, ties); to turn off (e.g. the light); to terminate (e.g. a conversation); to hang up (the phone); to punch (a ticket)
Examples (3 in total)
携帯のでんげんをきって、しまいなさい。
Turn off your phone and put it away.
トムはパソコンのでんげんをきりました。
Tom turned off the computer.
今、あなたがパソコンのでんげんをきれば、地球温暖化防止に貢献できる。
If you turned off your computer right now, you would contribute to the prevention of global warming.