Source : Webster's Revised Unabridged Dictionary (1913)

Membranaceous \Mem`bra*na"ceous\, a. [L. membranaceus.]
   1. Same as {Membranous}. --Arbuthnot.

   2. (Bot.) Thin and rather soft or pliable, as the leaves of
      the rose, peach tree, and aspen poplar.