Question

a word which describes a depressed area of land that has been drained by a river is

Answer 1

A word which describes a depressed area of land that has been drained by a river is basin.

Answer 2

Hello there mate :)

I️ believe the answer you are looking for is ‘basin’.
Basin, definition; depressedbasing expressed area of land that has been drained by a river.

Hope this helps >.<