The Collaborative International Dictionary of English v.0.48:

Polygraph \Pol"y*graph\, n. [Gr. ? writing much; poly`s much,
   many + ? to write: cf. F. polygraphe.]
   1. An instrument for multiplying copies of a writing; a
      manifold writer; a copying machine.
      [1913 Webster]

   2. In bibliography, a collection of different works, either
      by one or several authors. --Brande & C.
      [1913 Webster]
      [1913 Webster] Polygraphic

WordNet (r) 3.0 (2006):

polygraph
    n 1: a medical instrument that records several physiological
         processes simultaneously (e.g., pulse rate and blood
         pressure and respiration and perspiration)