Villain's cold -- nurse getting worried (9)
I believe the answer is:
scoundrel
'villain's' is the definition.
('scoundrel' can be a synonym of 'villain')
'cold nurse getting worried' is the wordplay.
'getting' says to put letters next to each other.
'worried' is an anagram indicator.
'cold'+'nurse'='coldnurse'
'coldnurse' is an anagram of 'SCOUNDREL'.
(Other definitions for scoundrel that I've seen before include "bad egg" , "Rat" , "Unprincipled rogue" , "Disreputable type" , "Person that's low" .)