The most common and most likely answer to this crossword clue is the 6 letter word SOBERS
S
O
B
E
R
S
Buddy explains!
The straight part
We know that "calms down" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case calms down = sobers.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 SOBERS mean?
SOBERS verb- (often with up) To make or become sober.
- (often with up) To overcome or lose a state of intoxication.
- To moderate one's feelings