Source : Webster's Revised Unabridged Dictionary (1913)

Rejuvenescence \Re*ju`ve*nes"cence\ (-n?s"sens), n.
   1. A renewing of youth; the state of being or growing young
      again.

   2. (Bot.) A method of cell formation in which the entire
      protoplasm of an old cell escapes by rupture of the cell
      wall, and then develops a new cell wall. It is seen
      sometimes in the formation of zo["o]spores, etc.