Consociation

Webster's Dictionary

(1):

(n.) A voluntary and permanent council or union of neighboring Congregational churches, for mutual advice and cooperation in ecclesiastical matters; a meeting of pastors and delegates from churches thus united.

(2):

(n.) Intimate union; fellowship; alliance; companionship; confederation; association; intimacy.

Cyclopedia of Biblical, Theological and Ecclesiastical Literature

(See Congregationalists).