Final answer:
The prefix that means "around" is 'peri-', such as 'perimeter' for the surrounding boundary of an area.
Step-by-step explanation:
The prefix meaning "around" is peri-. This prefix is used in various English words where it denotes 'around' or 'surrounding'. For example, in the term perimeter, 'peri' refers to the outline or boundary that surrounds an area. Another example is periscope, where 'peri' signifies looking around. It is not to be confused with the prefix inter-, which means "between", as in intercellular signaling, or intra- which means "inside" like in intravenous.