Noun
1. ellipse in which the two axes are of equal length; a plane curve generated by one point moving at a constant distance from a fixed point;
"he calculated the circumference of the circle"2. an unofficial association of people or groups;
"the smart set goes there""they were an angry lot"3. something approximating the shape of a circle;
"the chairs were arranged in a circle"4. movement once around a course;
"he drove an extra lap just for insurance"5. a road junction at which traffic streams circularly around a central island;
"the accident blocked all traffic at the rotary"6. street names for flunitrazepan
7. a curved section or tier of seats in a hall or theater or opera house; usually the first tier above the orchestra;
"they had excellent seats in the dress circle"8. any circular or rotating mechanism;
"the machine punched out metal circles"