Opinion piece (9)
(Another definition for oped that I've seen is " article in paper".)
'opinion piece' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for editorial that I've seen before include "Newspaper opinion piece" , "Article giving opinion of a newspaper" , "Article that states a newspaper's opinion" , "bit of paper" , "Newspaper article giving the editor's opinions" .)