The most common and most likely answer to this crossword clue is the 9 letter word HIERARCHY
I've seen this crossword clue in The Guardian
H
I
E
R
A
R
C
H
Y
More clues leading to the result HIERARCHY
- Under Henry I, archery revised pecking order
- Greeting with bow at end of day following queen’s order
- Making hay, richer can get up this
- An order to run railway over part of bridge
- Classified government order
- Grading Industrial Engineers as described by HR are key to the auditor
- Lengthier arc hypothetically contains vertical structure
Buddy explains!

The straight part
We know that "order" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case order = hierarchy.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 HIERARCHY mean?
HIERARCHY noun- A body of authoritative officials organized in nested ranks.
- A social, religious, economic or political system or organization in which people or groups of people are ranked with some superior to others based on their status, authority or some other trait.
- Any group of objects ranked so that every one but the topmost is subordinate to a specified one above it.