Leader in a column? (9)
I believe the answer is:
editorial
This clue is a double definition.
'leader' is the first definition.
(I've seen this before)
'a column?' is the second definition.
('editorial' can be a synonym of 'column')
'in' acts as a link.
(Other definitions for editorial that I've seen before include "bit of paper" , "Newspaper opinion piece" , "(Paper's) leader" , "Chief newspaper article" , "Newspaper item" .)