The most common and most likely answer to this crossword clue is the 6 letter word FELINE
I've seen this crossword clue in The Times
F
E
L
I
N
E
More clues leading to the result FELINE
- Extremely furtive row of cats
- Acceptable to house the Spanish cat
- Cat good catching mice and weasel finally
- Iron railway, perhaps of Persians
- Tiger maybe needing iron on course
- Cat first found by English river thrown back
- Metal chain, ounce perhaps?
- Persian for one using iron railway
- Tom is one following row on Twitter?
- Fake empty yarn about Tom?
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 = feline.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 FELINE mean?
FELINE adjective- Of or pertaining to cats.
- Catlike (resembling a cat)
- A cat; member of the cat family Felidae.