Piece of news often editorially toned down (8)
I believe the answer is:
softened
'toned down' is the definition.
('softened' can be a synonym of 'toned down')
'piece of news often editorially' is the wordplay.
'piece of' indicates a hidden word.
'SOFTENED' can be found hidden inside 'news often editorially'.
(Other definitions for softened that I've seen before include "Relented" , "Became tender" .)