Hi, I listened to this story on the radio today and immediately thought about some of the essays I have read over the years:
npr.org/2013/12/23/256570578 … flashcards
The point is that the dictionary definition or the synonyms for a word do not always tell you exactly where it will sound natural and where it won’t. For instance, esoteric is a synonym for obscure, but just because obscure will work in a sentence does not mean that you can use esoteric instead. “The professor taught in a small, obscure college far from the bustle of the city.” is good. “The professor taught in a small, esoteric college far from the bustle of the city.” is not.
I often find TOEFL essayists including a “fancy” word where it sounds a little odd and a simpler word is more natural. Unfortunately, the article does not give too much advice on increasing one’s vocabulary - I think there is no shortcut around reading as much as you can, paying close attention to new or unfamiliar words.
TOEFL listening lectures: Which characteristic of Ireland does the professor utilize in his lecture?