The word "circum" is often used as a prefix, and it means "around" or "surrounding." There are several synonyms that can be used in place of this word, depending on the context. For example, the word "periphery" can be used to describe the outer edge or boundary of something. Another synonym is "surroundings," which refers to the general area or environment around a specific location. "Ambiance" is another synonym that can be used to describe the overall atmosphere or mood of a place. Other synonyms for circum include "boundary," "enclosure," and "environs." These words can be used to add variety and depth to writing or speech.