Source : Webster's Revised Unabridged Dictionary (1913)

Areolation \A`re*o*la"tion\, n.
   1. Division into areol[ae]. --Dana.

   2. Any small space, bounded by some part different in color
      or structure, as the spaces bounded by the nervures of the
      wings of insects, or those by the veins of leaves; an
      areola.