Harry's noble, good man inside (6)
I believe the answer is:
pester
'harry's' is the definition.
(thesaurus)
'noble good man inside' is the wordplay.
'noble' becomes 'peer' (peer is a kind of noble).
'good man' becomes 'st'.
'inside' is an insertion indicator.
'peer' placed around 'st' is 'PESTER'.
(Other definitions for pester that I've seen before include "Trouble, annoy" , "Harass" , "Nag, badger" , "Be a nuisance, annoy with requests" , "Annoy persistently" .)