planar

adjective

1. 1

   Of or pertaining to a plane.

   “A planar projection of a three-dimensional object is its projection onto a plane.”

2. 2

   Flat, two-dimensional.

3. 3

   (of a graph) Able to be embedded in the plane with no edges intersecting.

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

4. 4

   (transistor chip, semiconductor devices) Having a flat profile, not etched into a mesa.