fail-safe /ˈfe(ə)lˌsef/
  故障無礙
  failsafe
  故障安全
  fail-safe
  故障安全
  fail-safe
       adj 1: guaranteed not to fail; "a fail-safe recipe for cheese
              souffle"
       2: eliminating danger by compensating automatically for a
          failure or malfunction; "a fail-safe device in a nuclear
          weapon to deactivate it automatically in the event of
          accident"