Merriam-Webster's Word of the Day for August 11, 2025 is stipulate. Stipulate means to demand or require something as part of an agreement. For instance, rules often stipulate player conduct. A famous opera singer, Christine Nilsson, could stipulate her preferred roles in her contracts. She could even prohibit other sopranos from performing those roles in the same season. The word stipulate entered English in the 17th century. It originates from the Latin word stipulari, meaning to demand a guarantee. In Roman law, stipulate was associated with the formal question-and-answer process for validating oral contracts. It also applied more broadly to any method of making agreements. The common modern meaning of stipulate, to specify a condition, also emerged in the 17th century.