Definition of heresiarch in US English:

heresiarch

noun

  • The founder of a heresy or the leader of a heretical sect.

    • ‘In its confrontation with heresiarchs, the Church learned to read the Scriptures in a way that should still inform us today.’
    • ‘So will there be wars of religion between orthodox Anglicans and heresiarchs in the break-away communions of North America?’
    • ‘The followers of Pelagius, a wicked Welsh heresiarch, had murdered the rightful king and his son and installed Vortigern, ‘a Pelagianized traytor against his Soveraign’ on the throne.’
    • ‘When the convocation met there were a great many sermons preached by various learned and eloquent divines, but nothing was produced which was pronounced by the general voice a satisfactory answer to the doctrines of the heresiarch.’
    • ‘One friend, an unregenerate Chippewa heresiarch himself, commented, ‘They've sure got the right one this time.’’

Origin

Mid 16th century: via ecclesiastical Latin from ecclesiastical Greek hairesiarkhēs ‘leader of a sect’, from hairesis ‘heretical sect, heresy’ + arkhēs ‘ruler’.

Pronunciation

heresiarch

/həˈrēzēärk//həˈriziɑrk/