The most common and most likely answer to this crossword clue is the 9 letter word KNEES-UPS
I've seen this crossword clue in The Guardian
K
N
E
E
S
-
U
P
S
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 KNEES-UPS mean?
KNEES-UPS noun- A party.