The Collaborative International Dictionary of English v.0.48:

Truchman \Truch"man\, n. [Cf. F. trucheman. See Dragoman.]
   An interpreter. See Dragoman. [Obs.]
   [1913 Webster]

         And after, by the tongue,
         Her truchman, she reports the mind's each throw. --B.
                                                  Jonson.
   [1913 Webster]