An object is Axisymmetric
if it has an axis from which the object is the same in any
direction. A disk, a sphere or cylinder is axisymmetric but a
cube is not.
In astrophysics, a Galaxy, a Circumstellar Disk, or planetary
rings as Saturn's may be virtually axisymmetric or mostly or generally not,
as may be a minor planet such as an Asteroid.