The most common and most likely answer to this crossword clue is the 8 letter word CAT-LIKE
I've seen this crossword clue in Financial Times
C
A
T
-
L
I
K
E
Buddy explains!

The straight part
We know that "Feline" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case feline = cat-like.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 CAT-LIKE mean?
CAT-LIKE adjective- Resembling a cat; feline
- Nimble, quick, graceful
- Slow, deliberate, quiet and stealthy