The prefix 'PERI' is derived from the Greek word for 'AROUND' or 'ABOUT'. It is commonly used to indicate something that is related to, or located near, a particular thing. For example, the word 'PERIMETER' refers to the outer boundary of an area, and 'periscope' refers to a device used to look AROUND corners. In general, the prefix 'PERI' is used to describe something that is related to, or located near, a particular thing.