Merriam-Webster's Word of the Day for September 14, 2025, is perpetuity. Perpetuity signifies a state of continuing forever or for an extended duration. It can be used to describe something passed down through generations. The word emphasizes the concept of infinite time or eternity. Perpetuity also holds specific legal and financial applications. These include arrangements in wills and annuities meant to be paid indefinitely. The term originates from the Latin word "perpetuus," meaning continual or uninterrupted. "Perpetuus" is the root for related words like "perpetuate" and "perpetual." A less common derivative, "perpetuana," refers to a historical type of durable wool fabric. Ultimately, the word conveys the idea of something lasting without end, though the text humorously notes that nothing is truly forever.