Wiktionary
adv. (form of mild form damn well English)
Usage examples of "darn well".
And he could darn well act macho and carry both packs if he wanted.
Then again, if the air conditioner continued to balk, she darn well might find herself crawling crawling out—.
All these executives know darn well what's going on in the hotel this week.
She knew darn well that her eyesight was less than perfect, but at the same time she knew what she'd seen at the computer lab.
You know darn well that those book clubs peddle those sex novels about small towns in which sex crimes are committed, and all the dirt comes to the surface.
Sunlight is good for roses and dahlias, but it would darn well finish off my fuchsias.
If Henry had crossed over from the spirit world to give a warning, then Joshua would darn well take it to heart.