Trough
WordNet
noun
(1) A channel along the eaves or on the roof; collects and carries away rainwater
(2) A container (usually in a barn or stable) from which cattle or horses feed
(3) A long narrow shallow receptacle
(4) A narrow depression (as in the earth or between ocean waves or in the ocean bed)
(5) A treasury for government funds
(6) A concave shape with an open top