The most common and most likely answer to this crossword clue is the 6 plus 3 letter word ROTTEN ROW
I've seen this crossword clue in The Guardian
R
O
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More clues leading to the result ROTTEN ROW
- Awful racket in road crossing Hyde Park
- Unpleasant argument in Hyde Park?
- Tired rider edges out round bridle path in capital
- Shabby Italian rider’s content to go up bridle path
- Rank upon rank that’s found running through Hyde Park
- Poor argument for London ride
- Track that consists of din fronted by singer Johnny
- Adverse criticism of Boat Race — it’s overridden
Buddy explains!
The straight part
We know that "in Hyde Park" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case in hyde park = rotten row.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.