The Collaborative International Dictionary of English v.0.48:

Partition \Par*ti"tion\, v. t. [imp. & p. p. Partitioned; p.
   pr. & vb. n. Partitioning.]
   1. To divide into parts or shares; to divide and distribute;
      as, to partition an estate among various heirs.
      [1913 Webster]

   2. To divide into distinct parts by lines, walls, etc.; as,
      to partition a house.
      [1913 Webster]

            Uniform without, though severally partitioned
            within.                               --Bacon.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

partitioning \partitioning\ n.
   An analysis into mutually exclusive categories.

   Syn: breakdown.
        [WordNet 1.5]

   2. Separation by the creation of a boundary that divides or
      keeps apart.

   Syn: division, partition, segmentation, subdivision.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

partitioning
    n 1: an analysis into mutually exclusive categories [syn:
         breakdown, partitioning]
    2: the act of dividing or partitioning; separation by the
       creation of a boundary that divides or keeps apart [syn:
       division, partition, partitioning, segmentation,
       sectionalization, sectionalisation]