Hospital worker fastens fur badly (5,5)
I believe the answer is:
staff nurse
'hospital worker' is the definition.
(I've seen this before)
'fastens fur badly' is the wordplay.
'badly' is an anagram indicator.
'fastens'+'fur'='fastensfur'
'fastensfur' is an anagram of 'STAFF-NURSE'.
(Other definitions for staff nurse that I've seen before include "tender below top level" , "sister senior to him" , "hospital worker" , "Senior healthcare professional" , "tender, helping sister" .)