The Collaborative International Dictionary of English v.0.48:

Adjacence \Ad"ja"cence\, Adjacency \Ad*ja"cen*cy\, [Cf. LL.
   adjacentia.]
   1. The state or attribute of being adjacent or contiguous;
      contiguity; the attribute of being so near as to be
      touching; as, the adjacency of lands or buildings.

   Syn: contiguousness
        [1913 Webster]

   2. That which is adjacent. [R.] --Sir T. Browne.
      [1913 Webster]