A more thorough explanation:

Plenarty (pronounced plee-nuh-tee or plen-uh-tee) is a historical term that refers to the state of being full or occupied. Specifically, it was used to describe the condition of a benefice that was lawfully occupied by an incumbent.

For example, if a church had a benefice, it meant that the church had a source of income or property that was used to support a priest or other religious official. When that benefice was occupied by someone who was authorized to hold it, such as a priest who had been appointed by the church, it was said to be in a state of plenarty.

Another example might be a piece of land that was owned by a lord or noble. If that land was being used by a tenant who had been granted the right to live there and work the land, then the land was said to be in a state of plenarty.

The term plenarty is not commonly used today, but it was an important concept in medieval and early modern Europe. It was used to describe the legal and social relationships between landowners, tenants, and religious institutions. By understanding the concept of plenarty, historians can gain insights into the ways in which power and authority were distributed in these societies.