(uncountable) The state or quality of being sullen. / (countable, rare) The result or product of being sullen.

plural of sullenness

Having a brooding ill temper; sulky. / Gloomy; dismal; foreboding. / Sluggish; slow. / (obsolete) Lonely; solitary; desolate. / (obsolete) Mischievous; malignant; unpropitious.

(obsolete) One who is solitary, or lives alone; a hermit. / (chiefly in the plural) Sullen feelings or manners; sulks; moroseness.

comparative form of sullen: more sullen

plural of sullen