A more thorough explanation:

Definition: A liferentrix is an archaic term used to describe a woman who has a liferent.

Example: In medieval times, a noblewoman might be granted a liferentrix, which would give her the right to live on and use a particular piece of land for the rest of her life.

Explanation: A liferent is a legal arrangement in which a person is granted the right to use or occupy a property for the duration of their life, without actually owning it. A liferentrix is simply a woman who has been granted this right. The example illustrates how a liferentrix might have been used in practice, by showing how a noblewoman might have been granted a liferentrix over a piece of land.