(n)circleellipse 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”
(n)traffic circle, circle, rotary, roundabouta road junction at which traffic streams circularly around a central island“the accident blocked all traffic at the rotary”
(n)circle, dress circlea 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”