minor league
In baseball, a minor league is a professional league that is not one of the major leagues.
minor league in American English
any league in a professional sport other than the major leagues
noun: any association of professional sports teams other than the major leagues, esp. when the member teams are associated with or controlled by major-league teams, which use them as training and proving teams for promising players
minor league in British English
noun: any professional league in baseball other than a major league
minor-league in American English
adjective: of or pertaining to a minor league