I think either the place with the words in the box or the set of agreed-upon ideas we follow when writing in this way should change so that we can bring new words into our shared set of words. I'm so used to being able to do this that not being able to do so makes writing in this way more of a pain than something to enjoy. To show what I mean, I might say that 'to define' means to set out a new word which the person who I'm speaking to might not know, and give them a way of knowing what I mean when I use that word later. That way, I can state ideas with less words: now that I have set out a meaning for the word 'define', the above could be written in a different way as 'I would like to be able to define new words'. In fact, I think that this would be so nice that I might try to define more and more words in an easy to read way until I'm able to write as usual without spending any time taking all of the words I usually use and putting bigger sets of shorter words in their place.