planar

adjective4

1. •
   Of or pertaining to a plane.

   • A planar projection of a three-dimensional object is its projection onto a plane.
2. •
   Flat, two-dimensional.
3. •
   Having a flat profile, not etched into a mesa.
4. •
   Able to be embedded in the plane with no edges intersecting.

   • A complete graph with more than four nodes is never planar.