The word 忧郁 (yōuyù) is formed by combining two characters that each convey a layer of the same heavy, emotional atmosphere. The first character, 忧, primarily means "worry" or "sorrow", establishing the core feeling. The second, 郁, means "gloomy", "dense", or "pent-up", and it acts to deepen and intensify that initial sorrow, suggesting it is not fleeting but a lingering, accumulated, and deeply rooted melancholy. Together, they create a composite image where sorrow becomes dense and stifling, visually and conceptually merging into the profound state of feeling "depressed" or "melancholic".