The whole prison sentence, unsurpassed up to now (3-4)
I believe the answer is:
all-time
'unsurpassed up to now' is the definition.
(as in an all-time record)
'the whole prison sentence' is the wordplay.
'the whole' becomes 'all' (I've seen this before).
'prison sentence' becomes 'time' (as in 'doing time').
'all'+'time'='ALL-TIME'
(Other definitions for all-time that I've seen before include "Unsurpassed to date" , "Best ever" , "Hitherto unsurpassed" , "As yet unsurpassed" , "So far unsurpassed" .)