The Collaborative International Dictionary of English v.0.48:

Copeman \Cope"man\, n. [D. koopman, fr. koopen to buy. See
   Cope, v. i. Chapman.]
   A chapman; a dealer; a merchant. [Obs.]
   [1913 Webster]

         He would have sold his part of paradise
         For ready money, had he met a copeman.   --B. Jonson.
   [1913 Webster]