The Collaborative International Dictionary of English v.0.48:

Aristate \A*ris"tate\, a. [L. aristatus, fr. arista. See
   Arista.]
   1. (Bot.) Having a pointed, beardlike process, as the glumes
      of wheat; awned. --Gray.
      [1913 Webster]

   2. (Zool.) Having a slender, sharp, or spinelike tip.
      [1913 Webster]