Not those in the Kentish area (5)
I believe the answer is:
these
'not those' is the definition.
(I've seen this in another clue)
'in the kentish area' is the wordplay.
'in' means one lot of letters goes inside another.
'kentish area' becomes 'es' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'the' enclosing 'es' is 'THESE'.
Can you help me to learn more?
(Other definitions for these that I've seen before include "Pronoun for people or things" , "See 13" , "The persons or things here" , "He set (anag)" , "Sheet (anag) -- pronoun" .)