Miler is a term used to describe a RUNNER who specializes in running long distances. It is derived from the name of the American RUNNER Steve Prefontaine, who was known for his ability to run the mile in record times. The term is often used to refer to any RUNNER who excels at running long distances, such as a marathon or half-marathon. Milers are usually highly trained athletes who have dedicated their lives to running and competing in long-distance races.