Merriam-Webster's Word of the Day for October 4, 2026 is: adventitious \ad-ven-TISH-us\ adjective Adventitious is a formal word that most often describes something that comes from an outside source, and is neither inherent nor innate. In botanical contexts especially, the word also describes something that arises or occurs sporadically, or not in the usual or expected location. // The house is like a museum—beautifully restored, full of period