To stipulate means to demand or require that something specific must be included as part of an agreement or arrangement. When you stipulate something, you're setting a clear condition that has to be met.

Imagine your parents agree to let you get a pet, but they stipulate that you must feed it every day and clean its cage weekly. They're making it a firm, non-negotiable requirement of the deal. If a teacher assigns a book report, she might stipulate that it must be at least three pages long and include quotes from the text. Those aren't optional: they're specified conditions you must meet.

The word appears often in contracts and formal agreements. A professional athlete might stipulate in his contract that he gets a private locker, or a landlord might stipulate that tenants can't have parties after 10 PM. In court, lawyers might stipulate to facts, meaning they agree to accept certain information as true without arguing about it, which saves time.

A stipulation is the specific requirement itself: “The main stipulation of the agreement was that all homework had to be finished before video games.” When something is stipulated, it's been clearly spelled out as a necessary part of the deal.