Source : Webster's Revised Unabridged Dictionary (1913)

Fenestrate \Fe*nes"trate\, a. [L. fenestratus, p. p. of
   fenestrare to furnish with openings and windows.]
   1. Having numerous openings; irregularly reticulated; as,
      fenestrate membranes; fenestrate fronds.

   2. (Zo["o]l.) Having transparent spots, as the wings of
      certain butterflies.