A partially ordered set is a circle order if it is isomorphic to a set of disks ordered by containment.
Circle Order
See also
Isomorphic Posets, Partially Ordered SetExplore with Wolfram|Alpha
Cite this as:
Weisstein, Eric W. "Circle Order." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/CircleOrder.html