n. 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
n. something approximating the shape of a circle
n. a curved section or tier of seats in a hall or theater or opera house; usually the first tier above the orchestra
n. any circular or rotating mechanism
n. 圆周, 社交圈, 循环, 范围
vt. 围着, 环绕
vi. 盘旋, 循环