public utility vs public-service corporation

public utility and public-service corporation both are nouns.

Word	Noun	Adjective	Verb	Adverb
public utility	Yes	No	No	No
public-service corporation	Yes	No	No	No

As nouns, public utility and public-service corporation are synonyms defined as:

public utility and public-service corporation: a company that performs a public service; subject to government regulation

Other synonyms of public utility include public utility company, utility.

public utility (noun)	public-service corporation (noun)
a company that performs a public service; subject to government regulation	a company that performs a public service; subject to government regulation