Report framing left-winger’s apathy (7)
I believe the answer is:
boredom
'apathy' is the definition.
(thesaurus)
'report framing left-winger's' is the wordplay.
'report' becomes 'boom' (I've seen this before).
'framing' is an insertion indicator.
'left-winger' becomes 'red' (red is a kind of left-winger).
'boom' enclosing 'red' is 'BOREDOM'.
(Other definitions for boredom that I've seen before include "no interest" , "Tedium, ennui" , "Mental state" , "Feeling" , "Monotony" .)