Hippopotomonstrosesquippedaliophobia is the fear of long words. Let that sink in... that long word means the fear of long words!  If you break it down a bit, it combines hippopotamus, monstrous, sesquipedalian (long word) and phobia (fear). Someone had fun with a pen and a dictionary for that one. Pretty clever. 

So, If you are in that boring work meeting you always show face for and suddenly feel a bit anxious when hearing a long word, it's a real thing. You may have to say the word very slowly, but it's a thing and you are not alone. What will they think of next?