conciliar

adj

1. (formal, uncommon)Of or pertaining to a council, especially an ecclesiastical council.

   “The next few years saw increasing tension between those wishing to develop this conciliar mechanism and successive popes seeking to build on the papacy's newly restored integrity.”

   “This was the era which witnessed the beginnings of the conciliar movement, which sought to subordinate the papacy to the decisions of Church Councils.”