1. (noun)circle ellipse in which the two axes are of equal length; a planecurve generated by one point moving at a constantdistance from a fixed point "he calculated the circumference of the circle"
2. (noun)set, circle, band, lot an unofficial association of people or groups
"the smart set goes there"; "they were an angry lot"
3. (noun)circle something approximating the shape of a circle "the chairs were arranged in a circle"
4. (noun)lap, circle, circuit movement once around a course "he drove an extra lap just for insurance"
5. (noun)traffic circle, circle, rotary, roundabout a roadjunction at which traffic streams circularly around a centralisland "the accident blocked all traffic at the rotary"
6. (noun)R-2, Mexican valium, rophy, rope, roofy, roach, forget me drug, circle streetnames for flunitrazepan