a.

1. 昏暗的；阴沉的
   That was a somber January day.

   那是一个阴沉的正月天。

2. 忧郁的；闷闷不乐的
   He had a somber expression on his face.

   他面容忧郁。

3. 严峻的
   His expression was somber as he listened to the report of the accident.

   他听着关于事故的报告时，脸部表情严峻。

4. （颜色等）暗淡的，灰暗的；朴实无华的
   She was dressed in somber black.

   她穿一身灰黑色衣服。