Progressive artist involved in false reporting (7)
I believe the answer is:
liberal
'progressive' is the definition.
('liberal' can be a synonym of 'progressive')
'artist involved in false reporting' is the wordplay.
'artist' becomes 'ra' (Royal Academician, member of Royal Academy of Arts).
'involved in' means one lot of letters goes inside another.
'false reporting' becomes 'libel'.
'ra' going into 'libel' is 'LIBERAL'.
(Other definitions for liberal that I've seen before include "Lavish" , "Favouring individual freedoms" , "In favour of policies of progress and reform" , "Tolerant and open-minded in Braille" , "Permissive about Braille" .)