"Not parsed ahead of time" might be the better qualification. At least in some forths you can cease parsing the file (in the "outer interpreter") at any point a

"Not parsed ahead of time" might be the better qualification. At least in some forths you can cease parsing the file (in the "outer interpreter") at any point and perform any kind of computation or IO that you've previously defined, and based on that do whatever you want with the rest of the text of the source file (or just the next couple of tokens if you want), including parsing it manually in some other manner than what the outer interpreter would do by default. I haven't gone that deep in lisp, but I hear reader macros allow something similar, though perhaps they might be more restrictive by requiring a transformation into valid lisp trees / values, whereas forth allows you to just do whatever, and if that happens to have the side effect of adding new functions to the dictionary, so be it.