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"