ductor

from The Collaborative International Dictionary of English v.0.48

Ductor \Duc"tor\, n. [L., fr. ducere to lead.]
   1. One who leads. [Obs.] --Sir T. Browne.
      [1913 Webster]

   2. (Mach.) A contrivance for removing superfluous ink or
      coloring matter from a roller. See {Doctor}, 4. --Knight.
      [1913 Webster]

   {Ductor roller} (Printing), the roller which conveys or
      supplies ink to another roller. --Knight.
      [1913 Webster]