- (usually prenominal) informal certain to succeed or meet expectations; assured
WordReference Random House Learner's Dictionary of American English © 2026
sure•fire /ˈʃʊrˌfaɪr, ˈʃɜr-/USA pronunciation
adj. [before a noun][Informal.]
WordReference Random House Unabridged Dictionary of American English © 2026- sure to work:a surefire plan.
sure•fire
(shŏŏr′fīər′, shûr′-),USA pronunciation adj.
- sure to work;
foolproof:a surefire moneymaking scheme.
- sure + fire 1915–20
Collins Concise English Dictionary © HarperCollins Publishers::
sure-fire adj