for certain adv. phr. 1. Without doubt; certainly; surely.
He couldn't tell for sure from a distance whether it was George or Tom.
He didn't know for certain which bus to 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.
[TahlilGaran] English Idioms Dictionary ▲