1. Of habitual bad temper; having an unpleasant disposition; surly; disagreeable; cross; peevish; fractious; crabbed; -- of people; as, an ill-natured person; an ill-natured disagreeable old man. Opposite of good-natured. [Narrower terms: argumentative, contentious, disputatious, disputative, litigious: atrabilious, bilious, dyspeptic, liverish: bristly, prickly, snappish, splenetic, waspish: cantankerous, crotchety, ornery: choleric, irascible, hotheaded, hot-headed, hot-tempered, quick-tempered, short-tempered: crabbed, crabby, cross, fussy, fussbudgety, grouchy, grumpy, bad-tempered, ill-tempered: cranky, fractious, irritable, peevish, peckish, pettish, petulant, testy, tetchy, techy: crusty, curmudgeonly, gruff, ill-humored, ill-humoured: dour, glowering, glum, moody, morose, saturnine, sour, sullen: feisty, touchy: huffish, sulky: misanthropic, misanthropical: misogynous: shirty, snorty ill-tempered or annoyed): shrewish, nagging, vixenish: surly, ugly] Also See: unpleasant.
2. Dictated by, or indicating, ill nature; spiteful. “The ill-natured task refuse.”
3. Intractable; not yielding to culture. [R.] “Ill-natured land.”
-- Ill-na*tured*ly, adv. -- Ill-na*tured*ness, n.
adj : having an irritable and unpleasant disposition; "an
ill-natured disagreeable old man" [ant: good-natured]