1. In Roman law: The property which a father allowed his child, or a master allowed his slave, to hold as his own: In modern times, John Johnson was only ten when his father gave him his own peculium, a savings book with a hundred dollars.
2. A private or exclusive possession, property, or appurtenance: The peculium Mildred inherited from her mother was a cameo, one which her great great grandmother had worn on many special occasions.