I recommend studying a simple Forth implementation. rwmj wrote a tutorial/x86 implementation, now widely called Jonesforth:

Main x86 source to bootstrap minimal interpreter/compiler: https://github.com/nornagon/jonesforth/blob/master/jonesfort...

Further Forth definitions: https://github.com/nornagon/jonesforth/blob/master/jonesfort...

rwmj gave some background in comments on the HN story: https://news.ycombinator.com/item?id=10187248