Having wide vocabulary puts you ahead when taking the TOEFL test. There is almost no difficulty on explaining your thoughts or finding the right words for your response. Despite the range of vocabulary, you have to know that there are some words that you should avoid using in the exam. In particular, jargons have to be avoided in your responses.
Jargons are words that are considered specific vocabulary used in a particular profession or field. These words often have concealed meanings that only people in that specific field understand the content. Because the TOEFL is an English fluency exam that mainly uses an academic English approach, using jargons should be avoided as tasks should be in the formal tone. Jargons will only confuse the rater or worst, obscure the content of the whole response.