Small island, close to front, private (6)
I believe the answer is:
secret
This clue could be a double definition.
'small island close' is the first definition.
'secret' can be an answer for 'close' (thesaurus). I am unsure of the 'small island' bit.
'front private' is the second definition.
'secret' can be an answer for 'private' (thesaurus). I'm not sure about the 'front' bit.
'to' acts as a link.
(Other definitions for secret that I've seen before include "Private; classified" , "Cloak and dagger" , "'Hidden, covert (6)'" , "Not seen or know by others" , "Private, or something private" .)