Consociation

noun

1. Friendly or cooperative association, as between groups or organizations.
2. A subdivision of an association having one dominant species of plant.
3. A political arrangement in which various groups, such as ethnic or racial populations within a country or region, share power according to an agreed formula or mechanism.
4. Intimate association of persons or things; fellowship; alliance; companionship; union.
5. In the United States, an ecclesiastical body substituted by some Congregational churches for a council.