This is a problem I have encountered a few times while writing my novel. To set it in context, my novel is set in a fantasy world completely created by me. The main character, the hero, is a young woman named Elissa. Now Elissa is constantly held back from reaching her potential due to the fact that she has a crippling fear of crowds. Her chapters are also narrated in the first person, so do I just tiptoe around it by using descriptions of it, or should I come right out and refer to it as enchlophobia? At one point I did put it in the book, but it seemed so out of place that this girl in this fantasy realm would refer to it as such. It also got me thinking about other technical words, and whether it matters too much to use them in the context of my novel, for the sake of avoiding explanation. Thoughts?