Minor league refers to a lower tier of professional sports that serves as a developmental league for aspiring athletes. There are a few synonyms that capture the essence of the minor league, such as the farm system, developmental league, minor circuit, and second-tier league. The farm system refers to baseball's minor league system, where players develop their skills before joining the major league. The developmental league is a more generic term that applies to any sport that has a lower tier of professional play. Meanwhile, the minor circuit and second-tier league signify that it is not the highest level of competition as it is considered below the major leagues.