Valley
WordNet
noun
(1) A long depression in the surface of the land that usually contains a river
WiktionaryText
Noun
- An elongated depression between hills or mountains, often with a river flowing through it.
- The area which drains into a river.
- Any structure resembling one, e.g., the meeting point of two pitched roofs.
- The internal angle formed by the intersection of two sloping roof planes.