noun A two-dimensional geometric figure, a line, consisting of the set of all those points in a plane that are equally distant from a given point (center).
The set of all points (x, y) such that (x − 1) + y = r is a circle of radius r around the point (1, 0).
noun A two-dimensional geometric figure, a disk, consisting of the set of all those points of a plane at a distance less than or equal to a fixed distance (radius) from a given point.
noun The orbit of an astronomical body.
noun A circle of latitude.
the 49th circle
noun A state of moving as to follow a circle; a route that forms a circle.
The troops spent ten minutes marching in circle.
noun Any shape, curve or arrangement of objects that approximates to or resembles the geometric figures.
Children, please join hands and form a circle.
noun Any thin three-dimensional equivalent of the geometric figures.
Cut a circle out of that sheet of metal.
noun A curve that more or less forms part or all of a circle.