circle: a round shape that has no beginning or end
circlet: a small circle; a ring or round band worn as an ornament, especially on the head
circuit: a path for an electrical current to flow around
circulate: to move around an area or a place, often returning to a starting point
circumference: the distance all the way around a circle
circumflex: bending around; curved
circumnavigate: to go completely around
circumrotate: to turn around like a wheel
circumspect: careful; careful to look all around before doing something
circumvent: to prevent something from happening by careful thinking; to get around something; to entrap