A remedy that won’t fail, as in Hard work is a sure cure for brooding. Originating in the late 1800s as an advertising slogan (Dr. Keck’s Sure Cure for Catarrh; first recorded in 1881), this rhyming phrase was soon extended to other matters.
adjective, Older Use. 1. real; genuine.
adjective 1. sure to work; foolproof: a surefire moneymaking scheme.
adjective 1. sure to work; foolproof: a surefire moneymaking scheme. adjective 1. (usually prenominal) (informal) certain to succeed or meet expectations; assured sure as shooting
adjective 1. not likely to stumble, slip, or fall. 2. proceeding surely; unerring: his surefooted pursuit of success.