loculus

from WordNet (r) 3.0 (2006)

loculus
    n 1: a small cavity or space within an organ or in a plant or
         animal [syn: {locule}, {loculus}]

from The Collaborative International Dictionary of English v.0.48

Loculus \Loc"u*lus\, n.; pl. {Loculi}. [L., little place, a
   compartment.]
   1. (Zool.) One of the spaces between the septa in the
      Anthozoa.
      [1913 Webster]

   2. (Bot.) One of the compartments of a several-celled ovary;
      loculament.
      [1913 Webster]