Doubt one working to follow hunt (8)
I believe the answer is:
question
'doubt' is the definition.
(I know that doubt can be written as question)
'one working to follow hunt' is the wordplay.
'one' becomes 'i' (Roman numeral).
'working' becomes 'on' (on can mean working or activated).
'to follow' is a charade indicator (letters next to each other).
'hunt' becomes 'quest' (synonyms).
'i'+'on'='ion'
'ion' put after 'quest' is 'QUESTION'.
(Other definitions for question that I've seen before include "Inquiry" , ""To be or not to be", for example" , "Interrogate or express doubt about" , "Call into doubt" , "Doubt; object to" .)