Know this word - Zyxuzpf the only place I can find it is in a book I just bought The Cat in the Hat by PD Eastman has a mistake been made?

I read on that it actually isn't a legal dictionary term but a made up Word by Dr. Seuss. I have the same book and I was looking for answers as well. So far as I can tell it is not a real Word.

Thanks - so it is pretty pathetic and un-professional they put a non existent Word in a "dictionary" isn't it.