The Collaborative International Dictionary of English v.0.48:

Neighbor \Neigh"bor\ (n[=a]"b[~e]r), n. [OE. neighebour, AS.
   ne['a]hgeb[=u]r; ne['a]h nigh + geb[=u]r a dweller, farmer;
   akin to D. nabuur, G. nachbar, OHG. n[=a]hgib[=u]r. See
   Nigh, and Boor.] [Spelt also neighbour.]
   1. A person who lives near another; one whose abode is not
      far off. --Chaucer.
      [1913 Webster]

            Masters, my good friends, mine honest neighbors.
                                                  --Shak.
      [1913 Webster]

   2. One who is near in sympathy or confidence.
      [1913 Webster]

            Buckingham
            No more shall be the neighbor to my counsel. --Shak.
      [1913 Webster]

   3. One entitled to, or exhibiting, neighborly kindness;
      hence, one of the human race; a fellow being.
      [1913 Webster]

            Which now of these three, thinkest thou, was
            neighbor unto him that fell among the thieves?
                                                  --Luke x. 36.
      [1913 Webster]

            The gospel allows no such term as "stranger;" makes
            every man my neighbor.                --South.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

neighbour \neighbour\, neighbouring \neighbouring\,
neighbourhood \neighbourhood\, neighbourly \neighbourly\
   Same as neighbor, neighboring, neighborhood,
   neighborly. [Chiefly Brit.]
   [PJC]

WordNet (r) 3.0 (2006):

neighbour
    n 1: a person who lives (or is located) near another [syn:
         neighbor, neighbour]
    2: a nearby object of the same kind; "Fort Worth is a neighbor
       of Dallas"; "what is the closest neighbor to the Earth?"
       [syn: neighbor, neighbour]
    v 1: live or be located as a neighbor; "the neighboring house"
         [syn: neighbor, neighbour]
    2: be located near or adjacent to; "Pakistan neighbors India"
       [syn: neighbor, neighbour]