Here are some examples:
* Perimeter: The boundary of a two-dimensional figure (around the outside).
* Periscope: A device that allows viewing around obstacles.
* Pericardium: The sac that surrounds the heart.
* Period: A recurring cycle of time (around and around).
* Peripheral: Relating to the outer edges or boundaries (around the center).
This root, however, can also have other meanings, such as "near" or "very" depending on the context.