water cannon vs hosepipe

water cannon and hosepipe both are nouns.

Word	Noun	Adjective	Verb	Adverb
water cannon	Yes	No	No	No
hosepipe	Yes	No	No	No

As nouns, hosepipe is a hypernym of water cannon; that is, hosepipe is a word with a broader meaning than water cannon:

water cannon: a hose (carried on a truck) that fires water under high pressure to disperse crowds (especially crowds of rioters)
hosepipe: a flexible pipe for conveying a liquid or gas

Other hypernyms of water cannon include hose.

water cannon (noun)	hosepipe (noun)
a hose (carried on a truck) that fires water under high pressure to disperse crowds (especially crowds of rioters)	a flexible pipe for conveying a liquid or gas