n.
   - a violent disturbance of the peace by a crowd. ▸archaic rowdy behaviour. 
- an impressively varied or lavish display:![]()  a riot of colour. 
- 
(a riot)
 informal a highly amusing or entertaining person or thing.
v.
   - take part in a riot.
- behave in an unrestrained way.
- archaic act in a dissipated way.
Phrase
  
    - read someone the Riot Act
 give someone a severe warning or reprimand. 
[from the name of a former act partly read out to disperse rioters.]
- run riot
 - behave or be displayed in a violent and unrestrained way.
- proliferate or spread uncontrollably.
 
 
  Derivative
  
  Etymology
  ME: from OFr. riote ‘debate’, from rioter ‘to quarrel’, of unknown ultimate origin.