Modest about page as material for newspaper (4)
I believe the answer is:
copy
'material for newspaper' is the definition.
'modest about page' is the wordplay.
'modest' becomes 'coy' (I've seen this before).
'about' indicates putting letters inside.
'page' becomes 'p'.
'coy' placed around 'p' is 'COPY'.
'as' is the link.
(Other definitions for copy that I've seen before include "Reproduce" , "Closely imitate" , "what's to be printed" , "written for paper" , "transcription" .)