The most common and most likely answer to this crossword clue is the 7 letter word POLYGON
I've seen this crossword clue in The Guardian
P
O
L
Y
G
O
N
More clues leading to the result POLYGON
- Figure former educational establishment has almost disappeared
- Figure girl who’d prepare tea-making departed for audition
- Figure almost left behind old college
- Reportedly, parrot’s lost shape
- Old educational establishment to work with new figure
- Figure how a child might explain a parrot’s flight
- Only GOP can make out the figure
- Figure revealed when girl reportedly has left to make the tea?
Buddy explains!

The straight part
We know that "shape" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case shape = polygon.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 POLYGON mean?
POLYGON noun- A plane figure bounded by edges that are all straight lines.
- The boundary of such a figure.
- (more generally) A figure comprising vertices and (not necessarily straight) edges, alternatingly.
- Such a figure and its interior, taken as a whole.