Pronunciation: (shut'ôf", -of"), [key]
1. an object or device that shuts (something) off: the automatic shutoff on a heater.
2. an act or instance of shutting off something, as an opening, a flow, or a service: a shutoff of electric power due to unpaid bills. Also,shut'-off".
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.