Suggest prisoner swallow note (8)
I believe the answer is:
intimate
'suggest' is the definition.
(intimating is a kind of suggesting)
'prisoner swallow note' is the wordplay.
'prisoner' becomes 'inmate' (inmate is a kind of prisoner).
'swallow' is an insertion indicator.
'note' becomes 'ti' (I've seen this in other clues**).
'inmate' placed around 'ti' is 'INTIMATE'.
(Other definitions for intimate that I've seen before include "state" , "Personal - hint - friend" , "Give hint to close friend?" , "cosy" , "Hint to a familiar friend" .)