Many words mentioned above, such as immediate or
set-optimizer change the “current” or “most recently
defined” word. Sometimes you want to change an earlier word. You
can do this with
Make nt the latest definition, which can be manipulated by
immediate and set-* operations. If you have used
(especially compiled) the word referred to by nt already, do
not change the behaviour of the word (only its implementation),
otherwise you may get a surprising mix of behaviours that is
not consistent between Gforth engines and versions.