It's in Kent, wild, this feline (6)
I believe the answer is:
kitten
'this feline' is the definition.
(I have seen 'Little feline' mean 'kitten' so perhaps 'feline' could also mean 'kitten')
'it's in kent wild' is the wordplay.
'in' means one lot of letters goes inside another.
'wild' indicates anagramming the letters.
'kent' is an anagram of 'kten'.
'it' inserted into 'kten' is 'KITTEN'.
(Other definitions for kitten that I've seen before include "Young feline animal" , "youngster" , "Young cat, ferret etc." , "found in litter" , "Young of a beaver" .)