Old renegade working to support independent speech (7)
I believe the answer is:
oration
'speech' is the definition.
(I know that speech can be written as oration)
'old renegade working to support independent' is the wordplay.
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'renegade' becomes 'rat' (I've seen this before).
'working' becomes 'on' (on can mean working or activated).
'to support' is a charade indicator (letters next to each other) (in a down clue, some letters hold up others).
'independent' becomes 'i'.
'on' after 'i' is 'ion'.
'o'+'rat'+'ion'='ORATION'
(Other definitions for oration that I've seen before include "A formal or public speech" , "An eloquent speech" , "Platform speech" , "A formal or ceremonial speech" , "A long ceremonial speech" .)