league
noun
1 he tried to form a league of chieftains:
alliance, confederation, confederacy, federation, union, association, coalition, combine, consortium, affiliation, guild, corporation, conglomerate, cooperative, partnership, fellowship, syndicate, compact, band, group, circle, ring;
bloc, faction, axis, congress, entente;
brotherhood, society, fraternity, coterie, lodge;
rare consociation, sodality.