Crude programme on the radio? (6)
I believe the answer is:
coarse
'crude' is the definition.
(synonyms)
'programme on the radio?' is the wordplay.
'programme' becomes 'course' (programme of study).
'on the radio?' shows a homophone (sound like) (I've seen 'on the radio' mean this).
'course' sounds like 'COARSE'.
(Other definitions for coarse that I've seen before include "Large-grained or rough to the touch" , "Boorish" , "Vulgar - unrefined" , "lacking in taste" , "Rough or crude, lacking refinement" .)