The Collaborative International Dictionary of English v.0.48:

Periotic \Per`i*o"tic\, a. [Pref. peri- + Gr. ?, ?, the ear.]
   (Anat.)
   Surrounding, or pertaining to the region surrounding, the
   internal ear; as, the periotic capsule. -- n. A periotic
   bone.
   [1913 Webster]