Source : Webster's Revised Unabridged Dictionary (1913)

Congregational \Con`gre*ga"tion*al\, a.
   1. Of or pertaining to a congregation; conducted, or
      participated in, by a congregation; as, congregational
      singing.

   2. Belonging to the system of Congregationalism, or to
      Congregationalist; holding to the faith and polity of
      Congregationalism; as, a Congregational church.

Source : WordNet®

congregational
     adj 1: relating to or conducted or participated in by a
            congregation; "congregational membership";
            "congregational singing"
     2: of or pertaining to or characteristic of a Congregational
        church [syn: {Congregationalist}]