Final answer:
The prefix 'Circum' means 'around' and is used to denote the idea of surrounding or encircling something, as seen in words like 'circumference' and 'circumnavigate'.
Step-by-step explanation:
The meaning of the prefix 'Circum' is 'around'. It is commonly used in various English words to denote something that is surrounding or encircling something else. For instance, in the term 'circumference', it refers to the enclosing boundary of a curved geometric figure, particularly a circle. Similarly, 'circumnavigate' implies to travel completely around something, often used in the context of sailing around the world. It is important to wrap your mind around this concept to understand the use of 'Circum' in different contexts. Another great example is 'circumspect', which means to be wary and unwilling to take risks, metaphorically looking around cautiously.