Source : Webster's Revised Unabridged Dictionary (1913)

Hysterology \Hys`ter*ol"o*gy\, n. [Gr. ?; ? the latter + ?
   discourse: cf. F. hyst['e]rologie.] (Rhet.)
   A figure by which the ordinary course of thought is inverted
   in expression, and the last put first; -- called also
   {hysteron proteron}.