Badgering (10)
'badgering' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for harassment that I've seen before include "Intimidating behaviour" , "Constant intimidation" , "Persecution" , "Means trash (anag.)" , "trouble?" .)
(Other definitions for nagging that I've seen before include "Annoying continually" , "Continually complaining or faultfinding" , "Constantly finding fault" , "Pestering, plaguing" , "Henpecking" .)