theorem

/ˈθɪrəm/
noun
  1. A statement or idea in mathematics or logic that can be proved to be true.
    • The Pythagorean theorem helps you find the length of a triangle's side.
    • In geometry class, we learned a new theorem about angles.
    • The mathematician spent years proving a famous theorem.
  2. A general rule or principle that is accepted as true, especially in science or philosophy.
    • The theorem of evolution explains how species change over time.
    • This philosophical theorem suggests that all knowledge comes from experience.
    • Economists often debate a theorem about supply and demand.