The Collaborative International Dictionary of English v.0.48:

Valley \Val"ley\, n.; pl. Valleys. [OE. vale, valeie, OF.
   val['e]e, valede, F. vall['e]e, LL. vallata, L. vallis,
   valles. See Vale.]
   [1913 Webster]
   1. 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.
      [1913 Webster]

            The valley of the shadow of death.    --Ps. xxiii.
                                                  4.
      [1913 Webster]

            Sweet interchange
            Of hill and valley, rivers, woods, and plains.
                                                  --Milton.
      [1913 Webster]

   Note: Deep and narrow valleys with abrupt sides are usually
         the results of erosion by water, and are called
         gorges, ravines, canyons, gulches, etc.
         [1913 Webster]

   2. (Arch.)
      (a) The place of meeting of two slopes of a roof, which
          have their plates running in different directions, and
          form on the plan a reentrant angle.
      (b) The depression formed by the meeting of two slopes on
          a flat roof.
          [1913 Webster]

   Valley board (Arch.), a board for the reception of the lead
      gutter in the valley of a roof. The valley board and lead
      gutter are not usual in the United States.

   Valley rafter, or Valley piece (Arch.), the rafter which
      supports the valley.

   Valley roof (Arch.), a roof having one or more valleys. See
      Valley, 2, above.
      [1913 Webster]

WordNet (r) 3.0 (2006):

valley
    n 1: a long depression in the surface of the land that usually
         contains a river [syn: valley, vale]

Moby Thesaurus II by Grady Ward, 1.0:

88 Moby Thesaurus words for "valley":
   abysm, abyss, arroyo, bottom, bottom glade, bottoms, box canyon,
   breach, break, canyon, cavity, chap, chasm, check, chimney, chink,
   cirque, cleft, cleuch, clough, col, comb, combe, corrie, coulee,
   couloir, crack, cranny, crevasse, crevice, cut, cwm, dale, defile,
   dell, dike, dingle, ditch, donga, draw, excavation, fault, fissure,
   flaw, flume, fracture, furrow, gap, gape, gash, gill, glen, gorge,
   groove, grove, gulch, gulf, gully, hole, hollow, incision,
   intervale, joint, kloof, leak, lunar rill, moat, notch, nullah,
   opening, pass, passage, ravine, rent, rift, rime, rupture,
   scissure, seam, slit, slot, split, strath, trench, trough, vale,
   void, wadi



Easton's 1897 Bible Dictionary:

Valley
   (1.) Heb. bik'ah, a "cleft" of the mountains (Deut. 8:7; 11:11;
   Ps. 104:8; Isa. 41:18); also a low plain bounded by mountains,
   as the plain of Lebanon at the foot of Hermon around the sources
   of the Jordan (Josh. 11:17; 12:7), and the valley of Megiddo (2
   Chr. 35:22).

     (2.) 'Emek, "deep;" "a long, low plain" (Job 39:10, 21; Ps.
   65:13; Cant. 2:1), such as the plain of Esdraelon; the "valley
   of giants" (Josh. 15:8), usually translated "valley of Rephaim"
   (2 Sam. 5:18); of Elah (1 Sam. 17:2), of Berachah (2 Chr.
   20:26); the king's "dale" (Gen. 14:17); of Jehoshaphat (Joel
   3:2, 12), of Achor (Josh. 7:24; Isa. 65:10), Succoth (Ps. 60:6),
   Ajalon (Josh. 10:12), Jezreel (Hos. 1:5).

     (3.) Ge, "a bursting," a "flowing together," a narrow glen or
   ravine, such as the valley of the children of Hinnom (2 Kings
   23:10); of Eshcol (Deut. 1:24); of Sorek (Judg. 16:4), etc.

     The "valley of vision" (Isa. 22:1) is usually regarded as
   denoting Jerusalem, which "may be so called," says Barnes (Com.
   on Isa.), "either (1) because there were several valleys within
   the city and adjacent to it, as the vale between Mount Zion and
   Moriah, the vale between Mount Moriah and Mount Ophel, between
   these and Mount Bezetha, and the valley of Jehoshaphat, the
   valley of the brook Kidron, etc., without the walls of the city;
   or (2) more probably it was called the valley in reference to
   its being compassed with hills rising to a considerable
   elevation above the city" (Ps. 125:2; comp. also Jer. 21:13,
   where Jerusalem is called a "valley").

     (4.) Heb. nahal, a wady or water-course (Gen. 26:19; Cant.
   6:11).


U.S. Gazetteer Counties (2000):

Valley -- U.S. County in Idaho
   Population (2000):    7651
   Housing Units (2000): 8084
   Land area (2000):     3677.821913 sq. miles (9525.514622 sq. km)
   Water area (2000):    55.840243 sq. miles (144.625558 sq. km)
   Total area (2000):    3733.662156 sq. miles (9670.140180 sq. km)
   Located within:       Idaho (ID), FIPS 16
   Location:             44.655511 N, 115.920089 W
   Headwords:
    Valley
    Valley, ID
    Valley County
    Valley County, ID


U.S. Gazetteer Counties (2000):

Valley -- U.S. County in Montana
   Population (2000):    7675
   Housing Units (2000): 4847
   Land area (2000):     4920.996217 sq. miles (12745.321151 sq. km)
   Water area (2000):    140.982250 sq. miles (365.142335 sq. km)
   Total area (2000):    5061.978467 sq. miles (13110.463486 sq. km)
   Located within:       Montana (MT), FIPS 30
   Location:             48.258176 N, 106.560531 W
   Headwords:
    Valley
    Valley, MT
    Valley County
    Valley County, MT


U.S. Gazetteer Counties (2000):

Valley -- U.S. County in Nebraska
   Population (2000):    4647
   Housing Units (2000): 2273
   Land area (2000):     568.108215 sq. miles (1471.393460 sq. km)
   Water area (2000):    2.405518 sq. miles (6.230264 sq. km)
   Total area (2000):    570.513733 sq. miles (1477.623724 sq. km)
   Located within:       Nebraska (NE), FIPS 31
   Location:             41.549826 N, 98.972085 W
   Headwords:
    Valley
    Valley, NE
    Valley County
    Valley County, NE


U.S. Gazetteer Places (2000):

Valley, NE -- U.S. city in Nebraska
   Population (2000):    1788
   Housing Units (2000): 760
   Land area (2000):     1.515030 sq. miles (3.923910 sq. km)
   Water area (2000):    0.033750 sq. miles (0.087411 sq. km)
   Total area (2000):    1.548780 sq. miles (4.011321 sq. km)
   FIPS code:            50020
   Located within:       Nebraska (NE), FIPS 31
   Location:             41.314199 N, 96.348250 W
   ZIP Codes (1990):     68064
   Note: some ZIP codes may be omitted esp. for suburbs.
   Headwords:
    Valley, NE
    Valley


U.S. Gazetteer Places (2000):

Valley, AL -- U.S. city in Alabama
   Population (2000):    9198
   Housing Units (2000): 4194
   Land area (2000):     9.741416 sq. miles (25.230150 sq. km)
   Water area (2000):    0.000000 sq. miles (0.000000 sq. km)
   Total area (2000):    9.741416 sq. miles (25.230150 sq. km)
   FIPS code:            78204
   Located within:       Alabama (AL), FIPS 01
   Location:             32.811387 N, 85.177938 W
   ZIP Codes (1990):     36854
   Note: some ZIP codes may be omitted esp. for suburbs.
   Headwords:
    Valley, AL
    Valley


U.S. Gazetteer Places (2000):

Valley-Hi, PA -- U.S. borough in Pennsylvania
   Population (2000):    20
   Housing Units (2000): 29
   Land area (2000):     0.504223 sq. miles (1.305932 sq. km)
   Water area (2000):    0.064571 sq. miles (0.167238 sq. km)
   Total area (2000):    0.568794 sq. miles (1.473170 sq. km)
   FIPS code:            79644
   Located within:       Pennsylvania (PA), FIPS 42
   Location:             40.026222 N, 78.196071 W
   ZIP Codes (1990):
   Note: some ZIP codes may be omitted esp. for suburbs.
   Headwords:
    Valley-Hi, PA
    Valley-Hi
    Valley, PA
    Valley