The most common and most likely answer to this crossword clue is the 10 letter word JOURNALESE
I've seen this crossword clue in The Daily Telegraph
J
O
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A
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More clues leading to the result JOURNALESE
Buddy explains!
The straight part
We know that "hackneyed style of writing" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case hackneyed style of writing = journalese.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 JOURNALESE mean?
JOURNALESE noun- A style of writing used in some newspapers and magazines, characterized by cliché, hyperbolic language and clipped syntax.