We've all been there: facing a lengthy, complex word that ignores the phonics we were taught in elementary school, unsure of not only its pronunciation, but also its meaning. These words, from autochthonous to esquamulose, are both terrifying and impressive. After all, if someone knows how to use them—and even say them—they must be quite smart. Yet before you begin stuffing every email and presentation with verbose prose, you might want to reconsider what others perceive to be intelligent.