The most common and most likely answer to this crossword clue is the 9 letter word BAPTISING
I've seen this crossword clue in Independent
B
A
P
T
I
S
I
N
G
Buddy explains!

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 BAPTISING mean?
BAPTISING verb- To perform the sacrament of baptism by sprinkling or pouring water over someone or immersing them in water.
- To dedicate or christen.
- Of rum, brandy, or any other spirits, to dilute with water.
- To ensure proper burning of a joint by moistening the exterior with saliva.