The Collaborative International Dictionary of English v.0.48:

Anacamptic \An`a*camp"tic\, a. [Gr. ? to bend back; ? back + ?
   to bend.]
   Reflecting of reflected; as, an anacamptic sound (and echo).
   [1913 Webster]

   Note: The word was formerly applied to that part of optics
         which treats of reflection; the same as what is now
         called catoptric. See Catoptrics.
         [1913 Webster]