Editor’s note: 2017 is the 500th anniversary of the Protestant Reformation. Once a month, we'll look at different aspects of the movement.

Many unfamiliar terms appear when studying the Reformation. Here’s what some of them mean: 

Indulgences

Indulgences were spiritual privileges or financial payments for forgiveness of sin. An indulgence was said to release a person from purgatory.

Purgatory

Purgatory was a place of temporary punishment where a person can be purified to enter heaven.

Tetzel

Johann Tetzel was a priest who sold indulgences for the building of St. Peter's Basilica in Rome. Tetzel used slogans such as, “As soon as a coin in coffer rings, the soul from purgatory springs.”

Theses

The sale of indulgences led Martin Luther to post 95 Theses for public debate. While today people think of a thesis as a long document students write to earn their doctorate degree, Luther’s theses were single statements in which he argued against the sale of indulgences and other practices.

Diet

A diet, pronounced dee-et, is a legislative meeting.

Worms

Worms, pronounced with a German accent, was a town where a diet was held. This meeting condemned Luther's teaching. Luther is said to have replied, "Here I stand. I can do no other. God help me" in response to orders to stop his complaints.

Excommunication

At the Diet of Worms, Luther’s refusal to renounce his teachings led to his excommunication from the Catholic Church, which meant he was not allowed to participate in the sacraments.

Sources: Webster’s New World Dictionary; reformationonline.com/glossary.htm; albany.edu/jmmh/vol3/creating_cdroms/glossary.htm; history.com/topics/reformation;

wscal.edu/personal-pages/a-brief-glossary-of-medieval-and-reformation-theology; britannica.com/topic/purgatory-Roman-Catholicism