Someone who is greatly inexperienced with the knowledge of Harry Potter
One overwhelmed by the great number of information that Potterheads know.
One who has little knowledge of the general plot.
One too lazy to read such a "large book".
One who watched a few Harry Potter movies, but still doesn't understand it.
One who may confuse character names, books, movies, etc.
One who doesn't understand the wonderful, amazing world of Harry Potter
One who does not know or understand what Pottermore
Person 1: I read Chapter 13 of the Chamber of Secrets and it was amazing! Don't you love the part how Harry learned about Hagrid's past?
Person 2: Is the Chamber of Secrets the one where the guy without the nose killed Harry? What's a Hagrid?
Person 1: You're such a Potter Noob.