agent provocateur

from WordNet (r) 3.0 (2006)

agent provocateur
    n 1: a secret agent who incites suspected persons to commit
         illegal acts [syn: {agent provocateur}, {provocateur}]

from Moby Thesaurus II by Grady Ward, 1.0

28 Moby Thesaurus words for "agent provocateur":
      agitator, agitprop, capper, catalyst, come-on man, decoy,
      demagogue, exciter, firebrand, fomenter, incendiary, inciter,
      inflamer, instigator, mischief-maker, plant, provocateur, provoker,
      rabble-rouser, ringleader, rouser, seditionary, seditionist, shill,
      stool pigeon, stoolie, troublemaker, urger