The definition of a sure thing is something definite, guaranteed or certain to happen.
An example of a sure thing is that a person will have to pay interest on credit card debt if he carries a balance and the card charges interest.
- something considered certain to win, succeed, etc.
- all right; OK: used interjectionally
An outcome that is certain or assured; a certainty: “Any respectable contrarian is tempted to think a recession is a sure thing” (Floyd Norris).
Of course; certainly: Sure thing, I'll be there!
(plural sure things)
- (US) That which is certain.