Writing concisely is something I discussed earlier on in the life of this blog.
What is it?
The narrowing down of sentences, words, etcetera.
Instead of using a really big word like “Hippopotomonstrosesquipedaliophobia” you could say “the fear of long words.” (You have to love the irony in the choice of describing the fear of long words.)
Which of those two looks more intimidating? I would bet the first one. This is what writing concisely is about. Using words that are hard and long needlessly just confuses the reader rather than making the author sound intelligent. Filling up space should never be the goal of the writer. Getting the point across is the most important goal of any author. Stick to it, even if it makes you come up short of the word count. Most readers would rather understand than read fluff.