Source : Webster's Revised Unabridged Dictionary (1913)

Tunicle \Tu"ni*cle\, n. [L. tunicula a little tunic, coat, or
   membrane, dim. of tunica a tunic: cf. OF. tunicle.]
   1. A slight natural covering; an integument.

            The tunicles that make the ball or apple of the eye.
                                                  --Holland.

   2. (R. C. Ch.) A short, close-fitting vestment worn by
      bishops under the dalmatic, and by subdeacons.