val·ley (v?l??)n. pl. val·leys 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 *vall?ta, from Latin vall?s; see wel- in Indo-European roots.]val?leyed adj.American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.valley (?væl?) n1. (Physical Geography) a long depression in the land surface, usually containing a river, formed by erosion or by movements in the earth’s crust2. (Physical Geography) the broad area drained by a single river system: the Thames valley. 3. any elongated depression resembling a valley4. (Architecture) the junction of a roof slope with another or with a wall5. (Physical Geography) (modifier) relating to or proceeding by way of a valley: a valley railway. [C13: from Old French valee, from Latin vallis]Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014val?ley (?væl i) n., pl. -leys. 1. an elongated depression between uplands, hills, or mountains, esp. one following the course of a stream. 2. an extensive, more or less flat, and relatively low region drained by a great river system. 3. any depression or hollow resembling a valley. 4. a low point or interval in any process, representation, or situation. 5. any place, period, or situation that is filled with fear, gloom, or the like: the valley of despair. 6. a depression or angle formed by the meeting of two inclined sides of a roof. [1250?1300; Middle English valeie, valey