Source : Webster's Revised Unabridged Dictionary (1913)

neighbor \neigh"bor\, v. t. [imp. & p. p. {Neighbored}; p. pr. &
   vb. n {Neighboring}.]
   1. To adjoin; to border on; tobe near to.

            Leisurely ascending hills that neighbor the shore.
                                                  --Sandys.

   2. To associate intimately with. [Obs.] --Shak.

Neighboring \Neigh"bor*ing\, a.
   Living or being near; adjacent; as, the neighboring nations
   or countries.

Source : WordNet®

neighboring
     adj 1: situated near one another; "neighbor states" [syn: {neighbor},
             {neighbour}, {neighboring(a)}, {neighbouring(a)}]
     2: having a common boundary or edge; touching; "abutting lots";
        "adjoining rooms"; "Rhode Island has two bordering states;
        Massachusetts and Conncecticut"; "the side of Germany
        conterminous with France"; "Utah and the contiguous state
        of Idaho"; "neighboring cities" [syn: {abutting}, {adjacent},
         {adjoining}, {conterminous}, {contiguous}, {neighboring(a)}]