doleful
Very sad and gloomy, with deep, lasting unhappiness.
Doleful means deeply sad and mournful, filled with a heavy, sorrowful feeling. When someone looks doleful, their face shows real grief or disappointment, with downturned eyes, slumped shoulders, and a general air of unhappiness.
You might hear doleful music at a funeral, slow and somber, matching the sad mood. A dog left alone might make doleful whining sounds, expressing loneliness and longing for its owner to return. In stories, characters sometimes speak in doleful voices when delivering bad news or expressing regret.
The word carries more weight than simply “sad.” Someone feeling doleful experiences genuine sorrow or melancholy, like a gray cloud of sadness that won't lift quickly. If you're disappointed about missing recess, that's ordinary sadness. Doleful describes something deeper and more persistent.
When Eeyore in Winnie-the-Pooh speaks in his characteristic gloomy way about losing his tail or expecting the worst, he's being doleful. His whole manner communicates a deep, persistent sadness that colors everything he says and does.