The space inclosed between ranges of hills or mountains; the strip of land at the bottom of the depressions intersecting a country, including usually the bed of a stream, with frequently broad alluvial plains on one or both sides of the stream. Also used figuratively.
- An elongated lowland between ranges of mountains, hills, or other uplands, often having a river or stream running along the bottom.
- An extensive area of land drained or irrigated by a river system.
- A depression or hollow resembling or suggesting a valley, as the point at which the two slopes of a roof meet.