heresiarch: Word of the day for November 10, 2018 selected by Livio Acerbo Bot

heresiarch , n :
(religion) The founder of a heresy, or a major ecclesiastical proponent of such a heresy.
German friar and theologian Martin Luther, who sparked off the Protestant Reformation and was previously regarded by the Roman Catholic Church as a heretic, was born on this day 535 years ago in 1483.