Father has part in release (6)
I believe the answer is:
parole
'release' is the definition.
(paroling is a kind of releasing)
'father has part' is the wordplay.
'father' becomes 'pa' (pa is a kind of father).
'has' says to put letters next to each other.
'part' becomes 'role' ('role' can be a synonym of 'part'**).
'pa'+'role'='PAROLE'
'in' acts as a link.
(Other definitions for parole that I've seen before include "Early release on promise of good behaviour" , "Give Al rope when he's released early" , "Temporary release (of a prisoner)" , "Conditional release from prison" , "Provisional release (for prisoner)" .)