WordRel.com

• an association of states or organizations or individuals for common action

  hypernym	union
  hyponym	Five NationsIroquois LeagueLeague of IroquoisSix Nations

• an association of sports teams that organizes matches for its members

  synonym	conference
  hypernym	association
  hyponym	baseball leaguebasketball leaguebig leaguebowling leaguebush leagueclassdivisionfootball leaguehockey leagueIvy Leaguemajor leaguemajorsminor leagueminors

• an obsolete unit of distance of variable length (usually 3 miles)

  hypernym	linear measurelinear unit
  mero part	international mileland milemimilestat mistatute mile

• unite to form a league

  hypernym

  unifyunite