The Collaborative International Dictionary of English v.0.48:

Catastasis \Ca*tas"ta*sis\, n. [NL., fr. Gr. ?, fr. ? to set;
   kata` down + ? to place.]
   1. (Rhet.) That part of a speech, usually the exordium, in
      which the orator sets forth the subject matter to be
      discussed.
      [1913 Webster]

   2. (Med.) The state, or condition of anything; constitution;
      habit of body.
      [1913 Webster]