1. An elongated lowland between ranges of mountains, hills, or other uplands, often having a river or stream running along the bottom.
2. An extensive area of land drained or irrigated by a river system.
3. A depression or hollow resembling or suggesting a valley, as the point at which the two slopes of a roof meet.

[Middle English valey, from Old French valee, from Vulgar Latin *vallāta, from Latin vallēs.]

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.