The Collaborative International Dictionary
minor league \minor league\ n. Sport) A league of professional sports teams less proficient than a major leagues. Players in the minor leagues generally are paid less than those in the major leagues, and their games attract less atention.
Note: Certain minor league sports teams are often owned by those owning a major league club, and the minor league clubs are used to provide practise and opportunity for evaluation for candidates who wish to play in the major leagues.
Syn: minor league.
Wiktionary
a. Having a quality less than the best possible. n. An association of sports teams that plays at a level below the major leagues of a sport.
WordNet
n. a league of teams that do not belong to a major league (especially baseball) [syn: minors, bush league]
Wikipedia
Minor leagues are professional sports leagues which are not regarded as the premier leagues in those sports. Minor league teams tend to play in smaller, less elaborate venues, often competing in smaller cities. This term is used in North America with regard to several organizations competing in various sports. They generally have lesser fan bases and smaller budgets.
The minor league concept is a manifestation of the franchise system used in North American sports, whereby the group of major league teams in each sport is fixed for long periods between expansions or other adjustments, which only take place with the consent of the major league owners. In Europe, and many other parts of the world, the football leagues have many divisions below the top-flight as part of the football pyramid. In other parts of the world there is usually either a system of annual promotion and relegation, meaning that clubs have no fixed status in the hierarchy, or there is only one professional league per country in each sport, rendering the major/minor distinction irrelevant.
Usage examples of "minor league".
But it was enough to get him into a poker game, and endless hours on endless train and bus rides from one minor league town to the next had honed his skills sharper than those of the local boys he sat down with.
We got minor league lucky on our hot car queries--an Olds was snatched two blocks from La Paloma.
In 1939, the one-time Cleveland Indians catcher participated in a publicity stunt set up by the San Francisco Seals, a minor league team, in which he was supposed to catch a ball dropped from an airplane flying at an altitude of 1,000 feet.