A more thorough explanation:

Definition: Nullius filius is a Latin term that means "son of no one" or "son of nobody".

Example: In medieval times, a child who was abandoned or found without any known parents was considered a nullius filius.

Explanation: The term nullius filius was used to describe a child who had no known parents or family. This could be because the child was abandoned, orphaned, or found without any identification. In medieval times, a nullius filius was often taken in by the church or a noble family and raised as a ward or servant. The term is still used today in legal contexts to refer to a person who has no legal father or whose father is unknown.