Nerdy kids come in many forms. When I was in junior high school (age somewhere between 12 and 15), my friends and I used to trade cool polysyllabic words. Despite my love of these little gems, I encourage you to ignore the temptation to employ thesaurus-supplied vocabulary in your personal statement or supplemental essay. I’m not talking about dancing around the word nonproliferation (six syllables) in favor of a multi-word alternative. Nor am I saying that you shouldn’t use the thesaurus when you’ve written “goals” over and over, and you need a different word (such as “objectives”) to express the same concept. But the Committee generally isn’t impressed by the sprinkling of big words throughout the essay, particularly when the writing isn’t that sophisticated overall.
If you’re interested in getting maximum value from your application essays, edit and re-edit. Pare down your paragraphs. Take out unnecessary modifiers. The best writing for these purposes will be clear and straightforward. You can save your sesquipedalian best for future policy papers.