Roguish nurse, they say, shows great spirit (9)
I believe the answer is:
archangel
'great spirit' is the definition.
'roguish nurse they say' is the wordplay.
'roguish' becomes 'arch' (I've seen this before).
'nurse they say' becomes 'angel' (common informal term for a nurse).
'arch'+'angel'='ARCHANGEL'
'shows' is the link.
(Other definitions for archangel that I've seen before include "What we call a port" , "Port in northern Russia, or senior heavenly messenger" , "Michael, for example - Russian port" , "one coming from above with message maybe" , "Gabriel, for example" .)