for sure

[for sure] or [for certain] {adv. phr.} 1. Without doubt;certainly; surely.

He couldn't tell for sure from a distancewhether it was George or Tom.

He didn't know for certain which busto take.

I know for certain that he has a car.

2. {slang}Certain.

"That car is smashed so badly it's no good any more.""That's for sure!"

Compare: SURE THING.