The most common and most likely answer to this crossword clue is the 9 letter word RECTANGLE
I've seen this crossword clue in The Times
R
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C
T
A
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More clues leading to the result RECTANGLE
- Figure reportedly shattered by outlook
- Shape central, eg quadrilateral
- Figure getting financial district in right muddle!
- Park initially tended by old German is thing with four corners
- Leisure facility with maze and tennis court at periphery
- Playground mat is a basic shape
- Shape emerges from half-hidden recess leading to confusion
- Treacle – no good for reshaping figure
- In general, bustling court figure
- Shape of playing field a mess
Buddy explains!

The straight part
We know that "quadrilateral" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case quadrilateral = rectangle.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 RECTANGLE mean?
RECTANGLE noun- A quadrilateral having opposing sides parallel and four right angles.