A more thorough explanation:

Definition: Neife (neef), n.[Law French] Hist. A person born into bondage or serfdom; specifically, a female serf. Also spelled naif; neif; niefe.

Example: "For the children of villeins were also in the same state of bondage with their parents; whence they were called in Latin, nativi, which gave rise to the female appellation of a villein, who was called a neife." (2 William Blackstone, Commentaries on the Laws of England 93–94 (1766))

This means that a neife is a female serf who was born into bondage or servitude. In medieval times, people who were born into serfdom were not free and had to work for their lord. They were not allowed to leave the land without permission and had to pay taxes to their lord. The example given shows how the term was used in the past and how it was related to the Latin term "nativi".