(as) sure as hell informal simile
Definitely, or absolutely
Though it was very dark, I'm sure as hell I saw her.
As sure as hell, I will attend the party tonight.
He sure as hell will quit smoking.
Another way to say "absolutely", "definitely" or "for sure"
Absolutely; definitely
For sure, without a doubt; presumptively true based on prior experience or proof.
1. Absolutely correct.
2. Utterly, completely, absolutely.
To do domething based on your emotions rather than for rational reasons
I can't believe that Tom beat his classmate. He's always the one who let his heart rule his head.