ornery
Disagreeable, stubborn, and troublesome to deal with; cantankerous.
informal
Seemingly here was an intruder who was violating custom. Moreover, the partners had come to look upon this exceedingly rich district as their exclusive property. And so their indignation was extreme. "The low-down, ornery cuss!" said Dobbs. "The nerve of him, crowdin' in on us, just as if there wasn't lots of other places for him to go!"
Troublesome to deal with in a good way; mischievous, prankish, teasing.
informal
Ordinary, commonplace; hence, inferior, plain-looking, unpleasant.
obsolete
Where it comes from
A contracted or dialectal pronunciation of ordinary. Sense 3 (“ordinary, commonplace”) was the earliest sense; the meaning of the word then shifted to “inferior, plain-looking, unpleasant”—presumably due to ordinariness—and finally to sense 1 (“disagreeable, stubborn, and troublesome to deal with”).
Adapted from the Wiktionary entry ornery (CC BY-SA 4.0).