Hustle harassed detective (6)
I believe the answer is:
sleuth
'detective' is the definition.
(I know that sleuth is a type of detective)
'hustle harassed' is the wordplay.
'harassed' indicates an anagram.
'hustle' with letters rearranged gives 'SLEUTH'.
(Other definitions for sleuth that I've seen before include "tracker" , "Bloodhound" , "Holmes, for one" , "Detective; play and film" , "Sherlock Holmes, for example" .)