Source : Webster's Revised Unabridged Dictionary (1913)

Pinnate \Pin"nate\, Pinnated \Pin"na*ted\, a. [L. pinnatus
   feathered, fr. pinna a feather. See {Pin} a peg, {Pen}
   feather.]
   1. (Bot.) Consisting of several leaflets, or separate
      portions, arranged on each side of a common petiole, as
      the leaves of a rosebush, a hickory, or an ash. See
      {Abruptly pinnate}, and Illust., under {Abruptly}.

   2. (Zo["o]l.) Having a winglike tuft of long feathers on each
      side of the neck.

   {Pinnated grouse} (Zo["o]l.), the prairie chicken.