The Collaborative International Dictionary of English v.0.48:

Schesis \Sche"sis\, n. [NL., fr. Gr. ?, fr. ?, ?, to have or
   hold. See Scheme.]
   1. General state or disposition of the body or mind, or of
      one thing with regard to other things; habitude. [Obs.]
      --Norris.
      [1913 Webster]

   2. (Rhet.) A figure of speech whereby the mental habitude of
      an adversary or opponent is feigned for the purpose of
      arguing against him. --Crabb.
      [1913 Webster] Schetic