HIPPOPOTOMONSTROSESQUIPEDALIOPHOBIA [aka HIPPOPOTOMONSTROSEQUIPPEDALIOPHOBIA]
[noun]
the fear of long words.
Etymology: from hippopotomonstrosesquipedalian, an extension of sesquipedalian, “a long word” with monstrum, “monster” and a truncated, misspelled form of hippopotamus, intended to exaggerate the length of the word itself and the idea of the size of the words being feared; combined with phobia.