n.

1. 忧郁
2. 布鲁斯（美国南部黑人的爵士音乐及舞步）
3. 美国陆海空军的蓝色制服

pl. n.

1. [treated as sing. or pl.] melancholic music of black American folk origin, typically in a twelve-bar sequence.
2. (the blues) informal feelings of melancholy, sadness, or depression.