Filthy carbuncle annoys nurses (7)
I believe the answer is:
unclean
'filthy' is the definition.
('unclean' can be similar in meaning to 'filthy')
'carbuncle annoys nurses' is the wordplay.
'nurses' indicates a hidden word (nurse can mean holding closely).
'UNCLEAN' is hidden within 'carbuncle annoys'.
(Other definitions for unclean that I've seen before include "Dirty, ritually impure" , "Dirty, needs a wash" , "Contaminated" , "taboo" , "Defiled" .)