The Collaborative International Dictionary of English v.0.48:

acrotic \a*crot"ic\ ([.a]*kr[o^]t"[i^]k), a. [Gr. 'akro`ths an
   extreme, fr. 'a`kros.]
   1. (Med.) Pertaining to or affecting the surface of the body.
      AS
      [1913 Webster]

   2. (Med.) Pertaining to acrotism. --Dorland.
      [AS]