The most common and most likely answer to this crossword clue is the 9 letter word GEOMETRIC
I've seen this crossword clue in The Guardian
G
E
O
M
E
T
R
I
C
More clues leading to the result GEOMETRIC
- Euclidean circle in stone square in Morecambe
- Sort of progression of cortege I’m organising
- Design style even squares will be seen in
- Making tiger come out of a pyramid, say
- ‘Simply patterned’ encountered in Virgilian poem, not good the second time
- Meet corgi barking in a regular pattern?
- Regarding figures, George’s satisfied: endlessly wealthy
- Gravity’s breaking up meteor heading to Icelandic cape according to mathematical theory
- Erotic gem represented design using simple shapes
Buddy explains!

The straight part
We know that "Euclidean" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case euclidean = geometric.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 GEOMETRIC mean?
GEOMETRIC adjective- Of or relating to geometry.
- Increasing or decreasing in a geometric progression.
- Using simple shapes such as circles, triangles and lines in a decorative object.