A more thorough explanation:

Definition: Gersumarius (jər-sə-mair-ee-əs) is an adjective used in historical contexts to describe someone who is finable or liable to be fined at the discretion of a feudal superior. For example, a villein who gave his daughter in marriage was considered gersumarius and was required to pay a fine to the lord.

Example: In medieval England, a villein who wanted to marry off his daughter had to pay a fine to the lord. This fine was known as a gersuma, and the villein was considered gersumarius until he paid it.

Explanation: The example illustrates how gersumarius was used in medieval England to describe someone who was liable to be fined. In this case, the villein was required to pay a fine to the lord for giving his daughter in marriage. Until he paid the fine, he was considered gersumarius.