The most common and most likely answer to this crossword clue is the 10 letter word SYSTEMISED
I've seen this crossword clue in The Guardian
S
Y
S
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D
Buddy explains!

The straight part
We know that "Imposed order" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case imposed order = systemised.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 SYSTEMISED mean?
SYSTEMISED verb- To arrange into a systematic order.
- To engage in a cognitive process described as the drive to analyze and construct systems.