heresiarch: Meaning and Definition of

he•re•si•arch

Pronunciation: (hu-rē'zē-ärk", -sē-, her'u-sē-), [key]
— n.
  1. a leader in heresy; the leader of a heretical sect.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.