Petrus (given name)
Petrus is a Latin name derived from the Greek meaning "rock", and is the common English prefix "petro-" used to describe rock-based substances, like petros-oleum or "rock oil." As the source of Peter, it is a common name for people from antiquity through the medieval era. In the Netherlands, Belgium and South Africa it remained a very common given name, though in daily life, many use less formal forms like "Peter", "Pierre", "Piet" and "Pieter".