Concerning the morning paper (4)
I believe the answer is:
ream
'paper' is the definition.
(I've seen this before)
'concerning the morning' is the wordplay.
'concerning' becomes 're' (both can mean on a particular topic).
'the morning' becomes 'am' (as in re:00 AM).
're'+'am'='REAM'
(Other definitions for ream that I've seen before include "Widen (hole) with borer; twenty quires" , "stock of paper" , "Five hundred sheets of paper" , "480 sheets of paper" , "Quantity of paper, about 500 sheets" .)