Morose (adjective)

1. Having a sullen or gloomy disposition; showing a brooding ill humor.
2. Having a melancholic or depressed mood.

Origin:

From the latin word "morosus" meaning "sullen" or "gloomy".

Examples:

1. He was known for his morose demeanor.
2. She was feeling morose after the break-up.
3. The morose weather matched his mood.
4. He was morose and didn't want to talk to anyone.
5. The morose atmosphere in the office was palpable.