Miscreant led Quentin in a muddle (10)
I believe the answer is:
delinquent
'miscreant' is the definition.
(thesaurus)
'led quentin in a muddle' is the wordplay.
'in a muddle' is an anagram indicator.
'led'+'quentin'='ledquentin'
'ledquentin' with letters rearranged gives 'DELINQUENT'.
(Other definitions for delinquent that I've seen before include "Neglectful of duty" , "Young offender" , "SECOND PART OF 22" , "guilty of a minor offence" , "Offender, maybe juvenile" .)