Pardon prisoner getting discharged (7)
I believe the answer is:
condone
'pardon' is the definition.
(I've seen this before)
'prisoner getting discharged' is the wordplay.
'prisoner' becomes 'con' (abbreviation for 'convict').
'getting' says to put letters next to each other.
'discharged' becomes 'done' (discharge can mean do or complete).
'con'+'done'='CONDONE'
(Other definitions for condone that I've seen before include "Approve, sanction" , "Nod once (anag) -- make allowances for" , "Excuse made" , "Forgive, sanction" , "Reluctantly sanction" .)