Harry is safe — son's in hiding (6)
I believe the answer is:
pester
'harry' is the definition.
(both can mean to bother)
'safe son's in hiding' is the wordplay.
'safe' becomes 'peter' (slang term for a safe).
'in hiding' indicates putting letters inside (some letters hide inside others).
'peter' placed around 's' is 'PESTER'.
'is' acts as a link.
(Other definitions for pester that I've seen before include "Annoy with persistent requests" , "Trouble persistently" , "Nag, badger" , "Annoy persistently" , "Be a nuisance, annoy with requests" .)