dup killer

from The Free On-line Dictionary of Computing (8 July 2008)

dup killer

   /d[y]oop kill'r/ Software that is supposed to detect and
   delete duplicates of a message that may have reached the
   {FidoNet} system via different routes.

   See also {dup loop}.

   [{Jargon File}]

   (1995-02-02)