fail-safe

1. Electronics. pertaining to or noting a mechanism built into a system, as in an early warning system or a nuclear reactor, for insuring safety should the system fail to operate properly.

2. equipped with a secondary system that insures continued operation even if the primary system fails.

3. (sometimes initial capital letter) of, relating to, or designating a system of coded military controls in which bombers dispatched to a prearranged point as part of a standard operating procedure cannot advance farther without direct orders from a designated authority and cannot have the nuclear warheads they carry armed until they have passed their prearranged point.

4. guaranteed to work; totally reliable.

   a fail-safe recipe for a cheese soufflé.

1. (sometimes initial capital letter) the point beyond which the bombers cannot go without specific instruction; the fail-safe point.

2. something designed to work or function automatically to prevent breakdown of a mechanism, system, or the like.

1. to make fail-safe.

1. designed to return to a safe condition in the event of a failure or malfunction

2. (of a nuclear weapon) capable of being deactivated in the event of a failure or accident

3. unlikely to fail; foolproof

1. (intr) to return to a safe condition in the event of a failure or malfunction