circle

n. 1 round plane figure whose circumference is everywhere equidistant from its centre. 2 circular or roundish enclosure or structure. 3 curved upper tier of seats in a theatre etc. 4 circular route. 5 persons grouped round a centre of interest. 6 set or restricted group (literary circles). v. (-ling) 1 (often foll. By round, about) move in a circle. 2 a revolve round. B form a circle round.  come full circle return to the starting-point. [latin diminutive: related to *circus]

n. A plane figure, bounded by a single curve line called its circumference, every part of which is equally distant from a point within it, called the center.