The Collaborative International Dictionary of English v.0.48:

Sedition \Se*di"tion\, n. [OE. sedicioun, OF. sedition, F.
   s['e]dition, fr. L. seditio, originally, a going aside;
   hence, an insurrectionary separation; pref. se-, sed-, aside
   + itio a going, fr. ire, itum, to go. Cf. Issue.]
   1. The raising of commotion in a state, not amounting to
      insurrection; conduct tending to treason, but without an
      overt act; excitement of discontent against the
      government, or of resistance to lawful authority.
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            In soothing them, we nourish 'gainst our senate
            The cockle of rebellion, insolence, sedition.
                                                  --Shak.
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            Noisy demagogues who had been accused of sedition.
                                                  --Macaulay.
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   2. Dissension; division; schism. [Obs.]
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            Now the works of the flesh are manifest, . . .
            emulations, wrath, strife, seditions, heresies.
                                                  --Gal. v. 19,
                                                  20.
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   Syn: Insurrection; tumult; uproar; riot; rebellion; revolt.
        See Insurrection.
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Moby Thesaurus II by Grady Ward, 1.0:

43 Moby Thesaurus words for "sedition":
   action, agitation, alienation, collaboration, coup, disaffection,
   estrangement, extremism, factiousness, fifth-column activity,
   fomentation, fraternization, high treason, instigation, insurgence,
   insurgency, insurgentism, insurrection, insurrectionism,
   lese majesty, misprision of treason, mutinousness, mutiny,
   petty treason, protest, putsch, quislingism, rabble-rousing,
   rebellion, rebelliousness, revolt, revolution, riotousness,
   seditiousness, stirring up, strike, subversiveness, traitorousness,
   treachery, treason, treasonableness, uprising, whipping up