planar

Etymology

From Late Latin plānārius (“relating to a plane”), derived from Latin plānus (“flat”, “level”), ultimately from Proto-Indo-European *pleh₂- (“flat”).

adj

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