copyholder

from WordNet (r) 3.0 (2006)

copyholder
    n 1: mechanical device used in printing; holds the copy for the
         compositor

from The Collaborative International Dictionary of English v.0.48

Copyholder \Cop"y*hold`er\, n.
   1. (Eng. Law) One possessed of land in copyhold.
      [1913 Webster]

   2. (print.)
      (a) A device for holding copy for a compositor.
      (b) One who reads copy to a proof reader.
          [1913 Webster]