from The American Heritage® Dictionary of the English Language, 4th Edition
- n. One who originates or is the chief proponent of a heresy or heretical movement.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. The founder of a heresy, or a major ecclesiastical proponent of such a heresy.
from the GNU version of the Collaborative International Dictionary of English
- n. A leader in heresy; the chief of a sect of heretics.
from The Century Dictionary and Cyclopedia
- n. A leader in heresy; an arch-heretic.
Late Latin haeresiarcha, from Late Greek hairesiarkhēs : Greek hairesis, sect; see heresy + Greek -arkhēs, -arch.(American Heritage® Dictionary of the English Language, Fourth Edition)
From Ecclesiastical Latin haeresiarcha, from ecclesiastical Medieval Greek ἁιρεσιαρχης (hairesiarkhēs) (“leader of a sect”), corresponding to heresy + -arch. (Wiktionary)