Favouring social reform (11)
(Other definitions for progressive that I've seen before include "Moving forward" , "Forward-looking or -moving" , "Socially reforming" , "Favouring change" , "Go-ahead" .)
(Other definitions for radical that I've seen before include "Fundamental - non-conformist" , "Extreme, ultra" , "One holding strong reformist views" , "Dial car in order to be drastic" , "Holding extreme political views" .)