Revolting sort (6)
'revolting sort?' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for rebel that I've seen before include "Rise up against authority" , "Authority fighter" , "One who opposes the powerful" , "Maverick" , "Insurrectionist" .)
(Other definitions for rioter that I've seen before include "One involved in civil unrest" , "Person engaged in disorder" , "unruly person in mob" , "hooligan" , "Troublemaker involved in disturbing the peace" .)