Green’s Dictionary of Slang

(US) unkindly.

1884		(con. c.1840) ‘Mark Twain’ Huckleberry Finn (2001) 201: It mine me er de time I treat my little ’Lizabeth so ornery.
1897		A.H. Lewis Wolfville 61: The ornery an’ ongrateful part is that the Princess sends one of her own peonies scoutin’ ’round in the hills to bring in this band of cattle-eaters onto us.
1905		R. Beach Pardners (1912) 49: Hosstyle and ornery to the whole world.