Refers to a sports league or similar organized competition group. Common in names like セ・リーグ (Central League) and パ・リーグ (Pacific League).
That team will join the Kanto league starting next year.
He is active in the professional baseball league.
This team won the league championship last year.
His team belongs to a professional league.
Major League Baseball; MLB; the Major Leagues
league match; league competition; round robin
professional league
women's league; female league
group stage; pool stage
Loanword from English 'league', adopted into Japanese primarily for sports contexts.