Which adjective describes someone who is silent and sullen?

The adjective "morose" is appropriate to describe someone who is silent and sullen because it specifically conveys a sense of gloominess and sulkiness. A morose individual often appears withdrawn and shows a lack of interest in their surroundings, which aligns with the characteristics of silence and a sulky demeanor.

In contrast, "peevish" refers to someone who is irritable or easily annoyed, which does not necessarily imply silence or sadness. "Jocular," on the other hand, describes someone who is playful or joking, quite the opposite of being silent or sullen. Lastly, "jaded" refers to someone who is tired or dulled because of overindulgence, which doesn’t capture the essence of silence and moodiness. Therefore, "morose" is the most fitting term for someone exhibiting those specific traits.