Horrifying thing not having capital for nurse (5)
I believe the answer is:
carer
'for nurse' is the definition.
(medical worker)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for carer that I've seen before include "One who looks after sick or disabled person at home" , "One looks after another" , "Person who attends to a dependent adult" , "One looking after another" , "One tending a person who needs assistance" .)