Bad back prodded by our hospital nurse (7)
I believe the answer is:
nourish
'nurse' is the definition.
(thesaurus)
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for nourish that I've seen before include "encourage growth" , "Provide with materials for life and growth" , "Foster or cherish, often with food" , "Give sustenance to" , "Provide with sustenance for growth" .)