1. A person who advocates or implements reforms, especially in social, political, or religious matters
He was a great reformer who changed the education system.
Ele foi um grande reformador que mudou o sistema educacional.
2. One who seeks to improve or correct something that is considered faulty or unjust
The reformer fought against corruption in government.
O reformador lutou contra a corrupção no governo.
3. In religious context, a person involved in reform movements, particularly the Protestant Reformation
Martin Luther was a Protestant reformer.
Martinho Lutero foi um reformador protestante.