The most common and most likely answer to this crossword clue is the 8 letter word GEOMETRY
I've seen this crossword clue in The Daily Telegraph
G
E
O
M
E
T
R
Y
More clues leading to the result GEOMETRY
- Arrangement made by George, getting me shot
- Tory EGM frantic about European subject
- Travel around eastern Maine to test some maths
- Remodelled game theory not a hard subject
- Travel round Spain with this writer to test some maths
- Little George encountered the Head of Rugby, having a yen for some mathematics
- Nerd cut short attempt to secure order in maths subject
- What may be found in school textbook, awful grey tome
- The study of lines and solids, strangely grey to me
- George Martin’s first to hear about Earl’s arrangement
Buddy explains!

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 GEOMETRY mean?
GEOMETRY noun- The branch of mathematics dealing with spatial relationships.
- (often qualified in combination) A mathematical system that deals with spatial relationships and that is built on a particular set of axioms; a subbranch of geometry which deals with such a system or systems.
- The observed or specified spatial attributes of an object, etc.