what is a martyr and can McMurphy be considered one? what is the theme developing here?

A Martyr is a person who voluntarily suffers as the penalty for not conforming to an ideology or religion. McMurphy refuses to conform to Nurse Ratched's dominance over the lives of the men in the ward. Instead of doing his time and leaving, he fights the forces of evil. He suffers so the other men can see truth and live a better life.