The captain had given that device to the Klingon leader personally- a final fail-safe method of communication.

The Red Cross has acknowledged this is not a fail-safe method and that some of its food has been looted in the past by clan factions.

No, there has to be some fail-safe method.

But the loose approach to retraining eating habits is probably not a fail-safe method, at least not for all dieters.

"It was an ingenious fail-safe method," Spock said.

Ms. de Neergaard offered what she says is a "fail-safe" method for planting the pots without removing the plants as I do.

Algebraic manipulation of the symbols in the equations would provide a fail-safe method of logical deduction: i.e. logic is reduced to a type of algebra.

Even extraordinary physical security measures, elaborate codes and fail-safe methods "become ineffective if the guards or their commanders are suborned, corrupted or simply disappear."

There isn't a fail-safe method of dodging a gazump, but there are ways to improve the odds.

Magnetic reversal is a fail-safe method of dating rock samples.