A leader in heresy the main of a sect of heretics
- A leader in heresy; the principle of a sect of heretics.
1620s, from Church Latin haeresiarcha, from Late Greek hairesiarkhes (see heresy + arch-).
(n.) A leader in heresy; the chief of a sect of heretics.
At the council of Frankfort in 794 Alcuin upheld the orthodox doctrine, and obtained the condemnation of the heresiarch Felix of Urgel.