Melancholic (adjective)

1. Feeling or showing a depressed mood characterized by sadness, pessimism, and a lack of energy or enthusiasm.
2. Being or causing a feeling of unhappiness, dejection, and sometimes hopelessness.
3. Having a sad and serious disposition.

Origin:

Late 16th century from greek μελαγχολία (melankholia), from μέλας (melas, "black") + χολή (kholē, "bile"). the original sense was "suffering from melancholy," later broadened to "characteristic of melancholy.".

Examples:

1. Her melancholic demeanor suggested that she was struggling with something.
2. The melancholic music filled the room with a sense of sadness.
3. The melancholic skies seemed to reflect the mood of the city.
4. His melancholic words left everyone in the room feeling down.
5. The melancholic tone of the play was in stark contrast to the lively music outside.