Definition of "watercannon" []

• A hose (carried on a truck) that fires water under high pressure to disperse crowds (especially crowds of rioters) (noun)

WordNet. Princeton University. 2010.

• "Tell that to blacks, chicanos and others who have taken part in peaceful protest only to be subject to dogs set on them, watercannon, teargas, mace, pepper spray. tasers and plain old billy clubs."
• "Would having served give you better planning & execution, or a more realistic understanding of how badly watercannon can mess up your day?"
• "YAOUNDE - At least one man was injured when police used teargas, clubs and watercannon to disperse hundreds of demonstrators demanding the authorities reopen the electoral registers for presidential elections."