back water

名词 back water:

1. a body of water that was created by a flood or tide or by being held or forced back by a dam
   同义词：backwater
2. any backward region that is isolated from the world and resists progress
   同义词：backwater

1. A mound of earth or stone built to hold back water or to support a roadway.
   堤用以阻挡水或支持公路而建造的土堆或石堆