the curve theoretically assumed by a perfectly flexible and inextensible cord of uniform density and cross section hanging freely from two fixed points
a rigid circular band of metal or wood or other material used for holding or fastening or hanging or pulling; "there was still a rusty iron hoop for tying a horse"
any circular or rotating mechanism; "the machine punched out metal circles"
a 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"
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; "he calculated the circumference of the circle"
something approximating the shape of a circle; "the chairs were arranged in a circle"