Ill-natured, a.
1. Of habitual bad temper; peevish; fractious; cross; crabbed; surly; as, an ill-natured person.
2. Dictated by, or indicating, ill nature; spiteful. "The ill-natured task refuse." Addison.
3. Intractable; not yielding to culture. [R.] "Ill-natured land." J. Philips. -- Ill`-na"tured*ly, adv. -- Ill`-na"tured*ness, n.
Shades of meaning
Fernald has no entry of its own for ill-natured; he lists it under morose.
He lists it without comment; the entries above explain its neighbors.