fail-safe

Adjective

• That does not cause undue damage in the event of failure.
• Designed to shut off for safety if an emergency occurs.

Noun

• A device, mechanism or measure designed to make something fail-safe.

Verb

• To compensate automatically, in the event of a failure.
• To make a device or mechanism fail-safe, or to add a fail-safe device or mechanism to an existing system.