surefire

[ shoo r-fahyuh r, shur- ]
/ ˈʃʊərˌfaɪər, ˈʃɜr- /

adjective

sure to work; foolproof: a surefire moneymaking scheme.

Origin of surefire

First recorded in 1915–20; sure + fire
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

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