Journalist admits staff morale finally is worn down (6)
I believe the answer is:
eroded
'is worn down' is the definition.
(I've seen this before)
'journalist admits staff morale finally' is the wordplay.
'journalist' becomes 'ed' (short for editor).
'admits' indicates putting letters inside.
'staff' becomes 'rod' (I've seen this before).
'finally' says to take the final letters.
The last letter of 'morale' is 'e'.
'rod'+'e'='rode'
'ed' placed around 'rode' is 'ERODED'.
(Other definitions for eroded that I've seen before include "Wore away" , "Worn away by weather or water" , "Worn away by time, wind or water" , "Worn away, ground down" , "Eaten away" .)