surefire \ˈ ̷ ̷| ̷ ̷\adjective Etymology:sure (I) + fire : certain to produce a usually specified or desired result : proved by experience to be reliable : dependable < a surefire device > < a surefire winner > < a surefire recipe > < made my production … — once an unpredictable operation — entirely surefire — New Yorker >