Septum

septum
    n 1: (anatomy) a dividing partition between two tissues or
         cavities
    2: a partition or wall especially in an ovary
    

Septum \Sep"tum\, n.; pl. {Septa}. [L. septum, saeptum, an
   inclosure, hedge, fence, fr. sepire, saepire, to hedge in,
   inclose.]
   1. A wall separating two cavities; a partition; as, the nasal
      septum.
      [1913 Webster]

   2. (Bot.) A partition that separates the cells of a fruit.
      [1913 Webster]

   3. (Zool.)
      (a) One of the radial calcareous plates of a coral.
      (b) One of the transverse partitions dividing the shell of
          a mollusk, or of a rhizopod, into several chambers.
          See Illust. under {Nautilus}.
      (c) One of the transverse partitions dividing the body
          cavity of an annelid.
          [1913 Webster]
    

29 Moby Thesaurus words for "septum":
      barrier, brattice, buffer, buffer state, bulkhead, bumper, cloison,
      collision mat, cushion, diaphragm, dissepiment, dividing line,
      dividing wall, division, fender, interseptum, mat, midriff,
      midsection, pad, panel, paries, partition, party wall,
      property line, separation, septulum, shock pad, wall