offbutton
nounUK /ˈɒfˌbʌtən/
US /ˈɔfˌbʌtən/
A button you press to make something stop working.
Press the offbutton to turn off the lamp.
OTHER MEANINGS
2. A control that ends a machine's operation completely.
The offbutton on the drill is easy to reach.
3. A way to stop a program or device from running.
Tap the offbutton in the app to close it.
4. The part of a remote that turns a device off.
He found the offbutton on the remote in the dark.