The most common and most likely answer to this crossword clue is the 7 plus 5 letter word MALTESE CROSS
I've seen this crossword clue in The Daily Telegraph
M
A
L
T
E
S
E
C
R
O
S
S
More clues leading to the result MALTESE CROSS
- Badge of knights or lesser mascot in new display
- Symbol of order getting islanders upset
- Symbol of old order making islanders angry
- Decoration of an island most careless, unfortunately
- St John Ambulance emblem‘s not a pedigree spaniel?
- Symbol of latecomers changing ship?
- Most careless way to set up a plant
Buddy explains!
The straight part
We know that "Symbol" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case symbol = maltese cross.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.