Daily pressure to copy and run (5)
I believe the answer is:
paper
'daily' is the definition.
(newspaper)
'pressure to copy and run' is the wordplay.
'pressure' becomes 'p' (scientific abbreviation).
'to copy' becomes 'ape' (ape can mean to copy or imitate).
'and' says to put letters next to each other.
'run' becomes 'r' (cricket abbreviation).
'p'+'ape'+'r'='PAPER'
(Other definitions for paper that I've seen before include "It's usually made from wood pulp" , "See 10/25/18/20" , "Alternative to scissors or stone?" , "daily read?" , "Telegraph, for example" .)