Prisoner gets nurse to compete (7)
I believe the answer is:
contend
'to compete' is the definition.
(synonyms)
'prisoner gets nurse' is the wordplay.
'prisoner' becomes 'con' (abbreviation for 'convict').
'gets' is a charade indicator (letters next to each other).
'nurse' becomes 'tend' (tend can mean to nurse or look after).
'con'+'tend'='CONTEND'
(Other definitions for contend that I've seen before include "Struggle in rivalry" , "Struggle (with someone)" , "Struggle; assert" , "Debate - contest - claim" , "fight" .)