The most common and most likely answer to this crossword clue is the 7 letter word QUASHED
I've seen this crossword clue in Financial Times
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More clues leading to the result QUASHED
Buddy explains!

The straight part
We know that "Subdued" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case subdued = quashed.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 QUASHED mean?
QUASHED verb- To defeat decisively.
- To crush or dash to pieces.
- To void or suppress (a subpoena, decision, etc.).