dark, dour, glowering, glum, moody, morose, saturnine, sour, sullen

showing a brooding ill humor; "a dark scowl"; "the proverbially dour New England Puritan"; "a glum, hopeless shrug"; "he sat in moody silence"; "a morose and unsociable manner"; "a saturnine, almost misanthropic young genius"- Bruce Bliven; "a sour temper"; "a sullen crowd"

• ill-natured — having an irritable and unpleasant disposition