Synonyms and related words :
agent provocateur, agitator, agitprop, catalyst, demagogue, exciter, firebrand, fomenter, gadfly, incendiary, inciter, inflamer, instigator, malcontent, meddler, mischief-maker, provocateur, provoker, rabble-rouser, ringleader, rouser, scandalmonger, seditionary, seditionist, stormy petrel, urger