Legal Definitions - agnatus

Definition: Agnatus is a term used in Roman law to describe a person who is related through the male line. This means that they are connected to their family through their father, grandfather, great-grandfather, and so on.

For example, if a man's father has a brother, that uncle is the man's agnatus. If the man's grandfather has a sister, her children are not his agnati because they are not related through the male line.

In Roman law, agnati were all individuals who were subject to the same patria potestas, or the power of the father. This included brothers, sisters, uncles, aunts, nephews, nieces, and other relatives who were not part of another family. The agnatic family was the civil issue of the state.