/ˈsʌl.ən.nəs/
He responded with adolescent sullenness.
For a minute the heavy sullenness of her face vanished.
bad-tempered and not speaking, either on a particular occasion or because it is part of your character 面有愠色的；闷闷不乐的；郁郁寡欢的
Bob looked pale and sullen.
鲍勃脸色苍白，闷闷不乐。
She gave him a sullen glare.
她满脸不高兴地瞪了他一眼。
sullen teenagers
面色阴郁的青少年
(literary) (of the sky or weather 天空或天气) dark and unpleasant 阴沉的
noun
sul·len·ly
sul·len·ness