n.

1. 后退；退回[U]
2. 凹处[C]
3. （经济的）衰退；衰退期[C][U]
   His factory closed down during the period of economic recession.

   他的工厂在经济衰退时期关闭了。

4. （唱师班等的）退场[U]

n.

1. a period of temporary economic decline during which trade and industrial activity are reduced.
2. chiefly Astronomy  the action of receding.