American Heritage Dictionaries normally feature about 70,000 entries. From that multitude, the editors have chosen 100 words that are neither obscure nor outlandish that could give middle schoolers more aplomb and aptitude in their verbal encounters. If you're not sure whether that is something you need, study this list.
Words selected by the Editors of the American Heritage® Dictionaries. Published by Houghton Mifflin Harcourt Publishing Company.