An area from which water drains into a particular lake, river, etc.; the catchment area of a large river includes its tributaries.
The area served by a local institution, such as a hospital or school, or by extension, a railway station.
An area which drains itself into a river.
An elongated depression cast between hills or mountains, often garnished with a river flowing through it.
Any structure resembling one, e.g. the interior angle formed by the intersection of two sloping roof planes.
To form the shape of a valley.