Summary: The prefix *circum-* which means "around" and the Latin root word *circ* which mean "ring" both are influential in making up English words. For instance, the prefix *circum-* gave rise to the words [*circum*]ference and [*circum*]stances, whereas the root *circ* gave rise to [*circ*]le and [*circ*]ulation. Clearly a [*circum*]ference is the bearing "around" a circle, whereas a [*circ*]le itself is in the form of a "ring."
