Subdued reporters in grass (9)
I believe the answer is:
repressed
'subdued' is the definition.
('repress' can be a synonym of 'subdue')
'reporters in grass' is the wordplay.
'reporters' becomes 'press' (I've seen this before).
'in' indicates putting letters inside.
'grass' becomes 'reed' (I've seen this before).
'press' going into 'reed' is 'REPRESSED'.
(Other definitions for repressed that I've seen before include "Kept bottled up" , "Pent up" , "Inhibited" , "withdrawn" , "Checked" .)