The most common and most likely answer to this crossword clue is the 6 letter word PLACID
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A
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More clues leading to the result PLACID
- Calm little place, attended by a group of detectives
- Fellow in Highland attire keeping cold and unemotional
- Place with a group of detectives becomes calm
- Leader of clan in tartan, serene
- Unruffled church leader wearing tartan cloth
- Retired medical practitioner's still content
- Place tart in cool
- Los Angeles Police Department is under pressure still
- Unruffled tartan worn by chief of clan
- Peaceful mountain climbing by detectives
Buddy explains!

The straight part
We know that "Quiet" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case quiet = placid.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 PLACID mean?
PLACID adjective- Calm and quiet; peaceful; tranquil