Antonyms of adj sullen

2 senses of sullen

Sense 1
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")

INDIRECT (VIA ill-natured) -> good-natured -- (having an easygoing and cheerful disposition; "too good-natured to resent a little criticism"; "the good-natured policeman on our block"; "the sounds of good-natured play")

Sense 2
heavy, lowering, sullen, threatening -- (darkened by clouds; "a heavy sky")

INDIRECT (VIA cloudy) -> clear -- (free from clouds or mist or haze; "on a clear day")

Similarity of adj sullen

2 senses of sullen

Sense 1
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 (vs. good-natured) -- (having an irritable and unpleasant disposition)

Sense 2
heavy, lowering, sullen, threatening -- (darkened by clouds; "a heavy sky")
       => cloudy (vs. clear) -- (full of or covered with clouds; "cloudy skies")