Villainous crimes upset social worker (9)
I believe the answer is:
miscreant
'villainous' is the definition.
(I've seen this before)
'crimes upset social worker' is the wordplay.
'upset' indicates an anagram.
'social worker' becomes 'ant' (ants are social insects).
'crimes' is an anagram of 'miscre'.
'miscre'+'ant'='MISCREANT'
(Other definitions for miscreant that I've seen before include "villain" , "Naughty boy!" , "Wrongdoer" , "criminal" , "Wretch" .)