morose
Gloomy, grumpy, and stuck in unhappy thoughts.
Morose means gloomy, sullen, and ill-tempered in a way that affects how you interact with others. A morose person broods and withdraws, often refusing to cheer up or engage with people around them.
When your friend sits in the corner at recess looking morose, she's wrapped up in dark thoughts and doesn't want to talk about it. A morose teenager might slouch at the dinner table, answering questions with grunts and sighs, radiating gloom.
The word suggests something darker than ordinary sadness. Someone feeling morose dwells on negative thoughts and resists attempts to brighten their mood. Think of Eeyore from Winnie-the-Pooh, always expecting the worst with his gloomy predictions and heavy sighs.
Morose differs from simply being quiet or thoughtful. A person can sit quietly while reading a good book, lost in concentration. But someone sitting morosely is lost in unhappy thoughts, and their mood can cast a shadow over everyone nearby. The word captures that particular combination of sadness, irritability, and stubborn refusal to snap out of it.