Petrus is the Latin form of the Greek name Πέτρος (pétros) meaning "rock",[1] 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.