What is Sulk ?
Sulk is (noun) a sulk, the sulks a pe- riod when you behave in a way which shows you are annoyed, often by refusing to speak to anyone She had a fit of the sulks and re- fused to talk to anyone. I don’t mind if she goes into a sulk, but she has to learn to do as she’s told.(verb) to show you are annoyed by not saying anything They’re sulking be- cause we didn’t invite them.
source: Easier English, Student Dictionary Upper Intermediate Level