The most common and most likely answer to this crossword clue is the 6 letter word PLANAR
I've seen this crossword clue in The Times
P
L
A
N
A
R
More clues leading to the result PLANAR
- Design upset person painting flat
- Two-dimensional chart artist turned over
- Flat design expert overlooking central heating
- Flat layout with outer bits for atelier
- Scheme artist set up in flat
- Flat design principal dispenses with central heating
- Develop plot beside a river flat
- Flat, as revealed by map, overlooking a river
- Criticise housing student and retired artist in flat
- Design by leading pair of architects for flat
Buddy explains!

The straight part
We know that "Two-dimensional" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case two-dimensional = planar.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does PLANAR mean?
PLANAR adjective- Of or pertaining to a plane.
- Flat, two-dimensional.
- (of a graph) Able to be embedded in the plane with no edges intersecting.
- (transistor chip, semiconductor devices) Having a flat profile, not etched into a mesa.