Elderly newsman, silver on top (4)
I believe the answer is:
aged
'elderly' is the definition.
('aged' can be a synonym of 'elderly')
'newsman silver on top' is the wordplay.
'newsman' becomes 'ed'.
'silver' becomes 'ag' (Ag is the chemical symbol for silver).
'on top' says to put letters next to each other (down clues only).
'ed' put after 'ag' is 'AGED'.
(Other definitions for aged that I've seen before include "not a modern copy" , "Very old, person or wine" , "Grew old" , "Geriatric" , "Became older" .)