A more thorough explanation:

MISTERY

Mistery (mis-tə-ree) is an old-fashioned word that means a business or trade.

During medieval times, people who worked with leather were part of the mistery of leatherworkers. They had their own guild and rules for how to make and sell their products.

Another example of a mistery is the mistery of bakers. Bakers were responsible for making bread and other baked goods, and they had their own guild as well.

These examples illustrate how mistery was used in the past to describe a specific trade or business. It was a way for people to organize themselves and regulate their work.