A safe-deposit box

Safe enough to store valuables securely

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

A document that grants safe passage through enemy territory in times of war. / A convoy or guard to protect a person in a foreign country.

(obsolete) To guarantee safe passage by granting such a document.

A food storage cabinet keeping its contents cool by evaporation of water from sides made of hessian.

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

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.

(computing) A troubleshooting mode of many operating systems in which most advanced functions are not activated.

(chiefly Britain, Australia, New Zealand) A seat in a legislature that is traditionally held by one political party because of the make-up of the local electorate.