Nurse of some patients is terrified (6)
I believe the answer is:
sister
'nurse' is the definition.
(a female nurse might be called sister)
'some patients is terrified' is the wordplay.
'some' indicates the answer is hidden within the clue (some parts of the word are used).
'SISTER' is hidden in the letters of 'patients is terrified'.
'of' acts as a link.
(Other definitions for sister that I've seen before include "twin?" , "A relative to resist" , "Relative in hospital?" , "Close relation" , "The nurse in charge" .)