Wiktionary
dead set against
a. (alternative form of dead against English)
Usage examples of "dead set against".
She led a cabal dead set against handing the Ku anything but his head.
You did what you did back then, but here you are, leading a government that's dead set against the kind of change you say you always wanted.
I was approached by other leaders who are dead set against this treaty renewal—.
He was a generation older than his companions and dead set against any alliance of convenience.
Flo had originally intended for the family to use all the rooms, but they seemed dead set against it.
But listen to what the meeting was about: they all, including Charles, and his mama, just flown in from Atlanta, are dead set against the Ferris-Jones nuclear power plant being built north of here.