waterworks vs public utility

waterworks and public utility both are nouns.

Word	Noun	Adjective	Verb	Adverb
waterworks	Yes	No	No	No
public utility	Yes	No	No	No

As nouns, public utility is a hypernym of waterworks; that is, public utility is a word with a broader meaning than waterworks:

waterworks: a public utility that provides water
public utility: a company that performs a public service; subject to government regulation

Other hypernyms of waterworks include public-service corporation, public utility company, utility.

waterworks (noun)	public utility (noun)
workplace where water is stored and purified and distributed for a community	a company that performs a public service; subject to government regulation
a public utility that provides water