A more thorough explanation:

Definition: Cotarius (k-tair-ee-s) is a term from Law Latin that refers to a type of serf who held land by paying rent and providing personal services to their lord. This type of serfdom was known as socage-tenure.

Example: Cotarius and coterellus serfs were also called cottagers. For example, a cotarius might pay rent to their lord and also provide labor on the lord's land, such as plowing fields or tending to livestock.

Explanation: The example illustrates how a cotarius would hold land by paying rent and providing personal services to their lord. This type of serfdom was common in medieval Europe, where many people were tied to the land and had to work for their lord in exchange for the right to live and farm on the land.