Detective involved in hustle? (6)
I believe the answer is:
sleuth
'detective' is the definition.
(I know that sleuth is a type of detective)
'involved in hustle?' is the wordplay.
'involved in' indicates anagramming the letters (involved can mean complex or confusing).
'hustle' is an anagram of 'SLEUTH'.
(Other definitions for sleuth that I've seen before include "Investigator (informal)" , "Olivier/Caine film" , "Bloodhound" , "Gumshoe" , "Track" .)