The most common and most likely answer to this crossword clue is the 8 letter word FLOUTING
I've seen this crossword clue in The Daily Telegraph
F
L
O
U
T
I
N
G
Buddy explains!

The straight part
We know that "Defying orders, perhaps" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case defying orders, perhaps = flouting.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 FLOUTING mean?
FLOUTING verb- To express contempt for (laws, rules, etc.) by word or action.
- To scorn.
- The act by which something is flouted.