trough

noun

1. 1

   a channel along the eaves or on the roof; collects and carries away rainwater

2. 2

   a container (usually in a barn or stable) from which cattle or horses feed

3. 3

   a long narrow shallow receptacle

4. 4

   a narrow depression (as in the earth or between ocean waves or in the ocean bed)

5. 5

   a treasury for government funds

6. 6

   a concave shape with an open top