(ORGANIZATION) [noun] [C] - a group of people or countries who join together because they have the same interestthe Arab LeagueThe UN's predecessor, the League of Nations, was a league of colonial powers and other countries.In league means making secret plans to do something, esp. illegal or wrong.The criminals had been in league with the owners of the company.I'm sure those two are in league.
LEAGUE
Meaning of LEAGUE in English
Cambridge English vocab. Кембриджский английский словарь. 2012