Dabbler, with new start, ultimately into employing encouragement of aggression (6,7)
I believe the answer is:
rabble-rousing
'dabbler with new start ultimately' is the definition.
I can't judge whether this definition defines the answer.
'employing encouragement of aggression' is the wordplay.
I cannot quite understand how this works, but
'employing' could be 'using' ('use' can be a synonym of 'employ') and 'using' is found in the answer.
'of' could be 'o' and 'o' is located in the answer.
The remaining letters 'rabbler' is a valid word which might be clued in a way I don't understand.
This may be the basis of clue (or it may be nonsense).
'into' is the link.
Can you help me to learn more?
(Other definitions for rabble-rousing that I've seen before include "Stirring up the passions of the crowd" , "Stirring up trouble" , "Intentionally inflaming the emotions of the mob" , "Stirring up unrest" , "Stirring up prejudices" .)