The Collaborative International Dictionary of English v.0.48:

Neighborhood \Neigh"bor*hood\, n. [Written also neighbourhood.]
   1. The quality or condition of being a neighbor; the state of
      being or dwelling near; proximity.
      [1913 Webster]

            Then the prison and the palace were in awful
            neighborhood.                         --Ld. Lytton.
      [1913 Webster]

   2. A place near; vicinity; adjoining district; a region the
      inhabitants of which may be counted as neighbors; as, he
      lives in my neighborhood.
      [1913 Webster]

   3. The inhabitants who live in the vicinity of each other;
      as, the fire alarmed all the neiborhood.
      [1913 Webster]

   4. The disposition becoming a neighbor; neighborly kindness
      or good will. [Obs.] --Jer. Taylor.
      [1913 Webster]

   Syn: Vicinity; vicinage; proximity.

   Usage: Neighborhood, Vicinity. Neighborhood is
          Anglo-Saxon, and vicinity is Latin. Vicinity does not
          commonly denote so close a connection as neighborhood.
          A neighborhood is a more immediately vicinity. The
          houses immediately adjoining a square are in the
          neighborhood of that square; those which are somewhat
          further removed are also in the vicinity of the
          square.
          [1913 Webster]

WordNet (r) 3.0 (2006):

neighborhood
    n 1: a surrounding or nearby region; "the plane crashed in the
         vicinity of Asheville"; "it is a rugged locality"; "he
         always blames someone else in the immediate neighborhood";
         "I will drop in on you the next time I am in this neck of
         the woods" [syn: vicinity, locality, neighborhood,
         neighbourhood, neck of the woods]
    2: people living near one another; "it is a friendly
       neighborhood"; "my neighborhood voted for Bush" [syn:
       neighborhood, neighbourhood]
    3: the approximate amount of something (usually used
       prepositionally as in `in the region of'); "it was going to
       take in the region of two or three months to finish the job";
       "the price is in the neighborhood of $100" [syn: region,
       neighborhood]
    4: an area within a city or town that has some distinctive
       features (especially one forming a community); "an ethnic
       neighborhood"

Moby Thesaurus II by Grady Ward, 1.0:

77 Moby Thesaurus words for "neighborhood":
   airspace, alentours, ambience, ambit, approach, approximation,
   area, belt, borderlands, circle, circuit, circumambiencies,
   circumjacencies, circumstances, closeness, compass, confines,
   context, continental shelf, convergence, corridor, country,
   department, district, division, entourage,
   environing circumstances, environment, environs, extent,
   foreground, gestalt, ground, habitat, heartland, hinterland,
   immediacy, immediate foreground, land, magnitude, matter, milieu,
   nearness, nighness, offshore rights, outposts, outskirts, part,
   parts, perimeter, periphery, place, precinct, precincts, premises,
   propinquity, proximity, purlieus, quarter, range, region, salient,
   section, situation, soil, space, suburbs, surroundings, terrain,
   territory, three-mile limit, total environment, tune,
   twelve-mile limit, vicinage, vicinity, zone