The Free On-line Dictionary of Computing (30 December 2018):

threaded code

    A technique for implementing virtual machine
   interpreters, introduced by J.R. Bell in 1973, where each
   op-code in the virtual machine instruction set is the
   address of some (lower level) code to perform the required
   operation.  This kind of virtual machine can be implemented
   efficiently in machine code on most processors by simply
   performing an indirect jump to the address which is the next
   instruction.

   Many Forth implementations use threaded code and nowadays
   some use the term "threading" for almost any technique used to
   implement Forth's virtual machine.

   (http://complang.tuwien.ac.at/forth/threaded-code.html).

   ["James R. Bell", "Threaded Code", CACM, 1973, 16, 6, pp
   370-372].

   ["An Architectural Trail to Threaded Code Systems", Kogge,
   P. M., IEEE Computer, March 1982].

   (1998-09-02)