The most common and most likely answer to this crossword clue is the 7 letter word QUIETEN
I've seen this crossword clue in Independent
Q
U
I
E
T
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N
More clues leading to the result QUIETEN
Buddy explains!

The straight part
We know that "still" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case still = quieten.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 QUIETEN mean?
QUIETEN verb- To make quiet.
- To become quiet.