surefire
Bound to work
Surefire describes something certain to succeed or produce the expected result: a surefire way to lose weight, a surefire hit.
The word carries confidence, sometimes overconfidence—what's promised as surefire doesn't always deliver.
Also spelled sure-fire.
Worthy of trust
- trustworthyWorthy of confidence
- reliableConsistently performing as expected
- consistentNot varying or contradicting
- unfailingNever failing or weakening
infallible · fail-safe · foolproof · bulletproof · watertight · tried-and-true · time-tested · proven
Promised with certainty
- certainFree from doubt
- definiteClearly established, not vague
- inevitableCertain to occur
- undeniableImpossible to contradict
unquestionable · absolute · positive · conclusive · indisputable · incontrovertible · unmistakable · inescapable
dependable
Worthy of trust
- trustworthyWorthy of confidence
- reliableConsistently performing as expected
- consistentNot varying or contradicting
unfailing · infallible · fail-safe · foolproof · bulletproof · watertight · tried-and-true · time-tested · proven · steadfast
guaranteed
Promised with certainty
- certainFree from doubt
- definiteClearly established, not vague
- inevitableCertain to occur
undeniable · unquestionable · absolute · positive · conclusive · indisputable · incontrovertible · unmistakable · inescapable · foregone
effective
Producing intended results
winning · successful · productive · decisive · impactful · knockout · killer · slamdunk · money · golden
success
Favorable outcome attained
victory · breakthrough · payoff · jackpot · score · result · homerun · lock · moneymaker · crowd-pleaser
- certaintycertain, sure, uncertain, definite, doubtful
- reliabilityreliable, dependable, trustworthy, consistent, faithful
- risk-freeguaranteed, secure, safe, protected, certain
surefiredoubtful
Uncertain of truth
questionable · dubious · iffy · uncertain · chancy
surefireunreliable
Not consistently performing
fallible · untrustworthy · undependable · inconsistent · erratic
unsure, assured, ensure, insure, insurance, reassure, assurance, ensured, insured