Prisoner died following sailor's escape (7)
I believe the answer is:
abscond
'escape' is the definition.
(thesaurus)
'prisoner died following sailor's' is the wordplay.
'prisoner' becomes 'con' (abbreviation for 'convict').
'died' becomes 'd'.
'following' means one lot of letters go next to another.
'sailor's' becomes 'abs' (abbreviation for able seaman).
'con'+'d'='cond'
'cond' after 'abs' is 'ABSCOND'.
(Other definitions for abscond that I've seen before include "Make off, do a runner" , "cut and run" , "scarper" , "Steal away" , "Run away from a legal process" .)