1. The male head of a household: The ancient law required that only the paterfamilias could sign the deed to the property.
2. In Roman Law, the head of a household having the authority belonging to that position: After he reached the legal age of the time, the youth was able to claim the authority of paterfamilias because he was old enough to be head of his family since his father had recently died.
3. Etymology: from Latin, literally, "master of a house, head of a family"; from pater, "father" + familias, "family".