The most common and most likely answer to this crossword clue is the 8 plus 1 letter word APPEASE} :
I've seen this crossword clue in The Daily Telegraph
A
P
P
E
A
S
E
}
:
Buddy explains!
The straight part
We know that "Pacify" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case pacify = appease} :.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 APPEASE} : mean?
APPEASE} : verb- To make quiet; to calm; to reduce to a state of peace; to dispel (anger or hatred).
- To come to terms with; to adapt to the demands of.