SAT Word of the Day PowerScore Test Preparation on November 17, 2011 at 10:00 PM Find me on: Facebook Google+ Tweet Pernicious (adj.) exceedingly harmful (pronounced "per-NISH-uhs") Example Sentence: The pernicious rumor could ruin several lives if permitted to spread. Create your own sentence and post it below. The best sentence will be entered to win a free SAT course. * We will choose a new winner each month. Good luck!