The most common and most likely answer to this crossword clue is the 10 letter word TROUSERING
I've seen this crossword clue in Financial Times
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Buddy explains!

The straight part
We know that "Wrongly pocketing" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case wrongly pocketing = trousering.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 TROUSERING mean?
TROUSERING verb- To put money into one's trouser pocket; to pocket.
- To legally remove funds from an organization for personal use.
- To secretively steal an item or money for personal use.
- Fabric for making trousers