Religious reformer (6,6)
I believe the answer is:
(Other definitions for martin luther that I've seen before include "German Protestant theologian, d. 1546" , "He reformed" .)
I've seen this clue in The Guardian.
Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.