something that is or is supposed to be a certain success, as a bet or a business venture:
He thinks that real estate is a sure thing.
2.
something assured; certainty:
It's a sure thing that he'll refuse to cooperate.
3.
surely; for sure; O.K.; roger (often used as an interjection).
Origin
1830-40, Americanism
Examples from the web for sure thing
That's not a sure thing, of course, so split at your own risk.
There is only one sure thing that will reduce or remove our human impact on the environment.
Such a modest boost is nowhere near a sure thing, but researchers are hoping to use the new data to try other combinations.
Even some environmental benefits are not a sure thing.
Even if the programme is designed perfectly, it is no sure thing it will end the crisis.
In each case, one of the options would be a fifty-fifty bet and the other would be a sure thing.
And one sure thing about a system as complex as agriculture is that things will go wrong, often with devastating consequences.
Don't bother pursuing an impossible dream when a sure thing is staring you right in the face.
If it's a truly scarce sure thing, you won't get the call.
Even when owners find willing buyers, getting their price isn't a sure thing.
British Dictionary definitions for sure thing
sure thing
adverb
1.
(sentence substitute) (mainly US) all right! yes indeed! used to express enthusiastic assent
noun
2.
something guaranteed to be successful
Slang definitions & phrases for sure thing
sure thing
affirmation
Yes; certainly; willingly: Sure thing I'll go with you(1896+)
Idioms and Phrases with sure thing
sure thing
.
a sure thing. A certainty, as in Making the bestseller list has been a sure thing for Stephen King. This usage originally alluded to a bet that one could not lose. [ First half of 1800s ]
.
Yes indeed, certainly, as in Are you coming tonight?—Sure thing! This use of the idiom as an interjection dates from the late 1800s.