The most common and most likely answer to this crossword clue is the 9 letter word GRIMALKIN
G
R
I
M
A
L
K
I
N
Buddy explains!
The straight part
We know that "Cat" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case cat = grimalkin.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 GRIMALKIN mean?
GRIMALKIN noun- A cat, especially an elderly female.
- A bad-tempered old woman; a crone.