or "middle age", first recorded in 1604, and media saecula, or "middle centuries", first recorded in 1625. The adjective "medieval" (or sometimes "mediaeval" or "mediæval"), meaning pertaining to the Middle Ages, derives from medium aevum.

Medieval writers divided history into periods such as the "Six Ages" or the "Four Empires" and considered their time to be the last before the end of the world. When referring to their own times, they spoke of them as being