The Collaborative International Dictionary of English v.0.48:

Riot \Ri"ot\, v. i. [imp. & p. p. Rioted; p. pr. & vb. n.
   Rioting.] [OF. rioter; cf. OD. ravotten.]
   1. To engage in riot; to act in an unrestrained or wanton
      manner; to indulge in excess of luxury, feasting, or the
      like; to revel; to run riot; to go to excess.
      [1913 Webster]

            Now he exact of all, wastes in delight,
            Riots in pleasure, and neglects the law. --Daniel.
      [1913 Webster]

            No pulse that riots, and no blood that glows.
                                                  --Pope.
      [1913 Webster]

   2. (Law) To disturb the peace; to raise an uproar or
      sedition. See Riot, n., 3. --Johnson.
      [1913 Webster]

WordNet (r) 3.0 (2006):

rioting
    n 1: a state of disorder involving group violence [syn:
         rioting, riot]

Moby Thesaurus II by Grady Ward, 1.0:

20 Moby Thesaurus words for "rioting":
   assault, attack, battering, butchery, disorderliness,
   forcible seizure, killing, laying waste, looting, massacre,
   obstreperousness, onslaught, pillaging, rape, riot, sacking,
   slaughter, sowing with salt, unruliness, violation