Deader than Hell

Often seen or heard in the southern region of the United States, it is a terminology that refers to something being dead, or having been dead for a time. Often pronounced, 'deader'n hell,' given the draw of the person saying it.

Billy: "Lookie there, Cletus! Them there's a possum on the road. Looks like it might've got hit a week or so ago."

Cletus: "Mmm. Yep. Deader than Hell."