Fear of long words is hippopotomonstrosesquipedaliophobia, which is, appropriately, the longest name on the list, and I trust no reader of mine suffers from pogonophobia, which is a fear of beards.
The fear of long words is hippopotomonstrosesquipedaliophobia, which is 35 words long, but, because it is a phobia, this is viewed as a technical word.