from
The Collaborative International Dictionary of English v.0.48
Congregationalism \Con`gre*ga"tion*al*ism\, n.
1. That system of church organization which vests all
ecclesiastical power in the assembled brotherhood of each
local church.
[1913 Webster]
2. The faith and polity of the Congregational churches, taken
collectively.
[1913 Webster]
Note: In this sense (which is its usual signification)
Congregationalism is the system of faith and practice
common to a large body of evangelical Trinitarian
churches, which recognize the local brotherhood of each
church as independent of all dictation in
ecclesiastical matters, but are united in fellowship
and joint action, as in councils for mutual advice, and
in consociations, conferences, missionary
organizations, etc., and to whose membership the
designation "Congregationalists" is generally
restricted; but Unitarian and other churches are
Congregational in their polity.
[1913 Webster]