1 [U] a feeling of unhappiness that lasts for a long time. Depression can be a medical condition and may have physical signs, for example being unable to sleep, etc 沮丧；消沉；抑郁症（有失眠等症状）: clinical/post-natal depression 临床╱产后抑郁症

2 [C,U] a period when the economic situation is bad, with little business activity and many people without a job 不景气；萧条（期）: The country was in the grip of (an) economic depression. 这个国家正处于经济萧条期。

3 [C] a part of a surface that is lower than the parts around it 凹地；坑: Rainwater collects in shallow depressions in the ground. 雨水积聚在地上的浅坑里。

4 [C] (technical术语) a weather condition in which the pressure of the air becomes lower, often causing rain 低气压 ☞Compare anticyclone. 与anticyclone比较。