A good journalist over the hill? (4)
I believe the answer is:
aged
'over the hill?' is the definition.
(I've seen this before)
'a good journalist' is the wordplay.
'a good' becomes 'ag' (I've seen this in other clues**).
'journalist' becomes 'ed' (short for editor).
'ag'+'ed'='AGED'
(Other definitions for aged that I've seen before include "Mature" , "Geriatric" , "Long in the tooth" , "Got older" , "Advanced in years" .)