Struggle to get prisoner to nurse (7)
I believe the answer is:
contend
'struggle' is the definition.
(I know that struggle can be written as contend)
'get prisoner to nurse' is the wordplay.
'get' is a charade indicator (letters next to each other).
'prisoner' becomes 'con' (abbreviation for 'convict').
'to nurse' becomes 'tend' (tend can mean to nurse or look after).
'con' put next to 'tend' is 'CONTEND'.
'to' is the link.
(Other definitions for contend that I've seen before include "Struggle; assert" , "fight" , "Compete, vie" , "Compete; deal (with)" , "Struggle (with someone)" .)